Data Scientist

🏢 Summary: Data Scientist role focused on developing and deploying advanced machine learning models to enhance a large-scale Product Catalog, ensuring data quality, duplicate detection, and intelligent selection systems. The position covers the full lifecycle from ideation to production, working with massive datasets and diverse data types including NLP, images, spatial and time series data. The offer emphasizes strong MLOps practices, Spark-based processing, and cutting-edge GenAI solutions in a cloud environment. 🗂️ Requirements: Hands-on experience with Spark or PySpark, Practical experience building automated ML pipelines and deploying models to production, Strong Python programming skills with object-oriented design and unit testing, Solid knowledge of statistics and machine learning, Ability to select, evaluate and validate ML models properly, Understanding of GenAI principles including prompting and validation, Experience translating business problems into ML solutions, Degree in quantitative field or equivalent Data Science experience 📃 Skills: Python, Spark, PySpark, GCP, BigQuery, VertexAI, Cloud, Composer, Dataflow, Airflow, MachineLearning, Statistics, GradientBoosting, Bayesian, CausalInference, Optimization, DeepLearning, GenAI, LLMs, AgenticAI, NLP, MLOps, GitHub, Docker, Kubernetes 🏢 Description: Our team drives the solutions that build a trustworthy marketplace. As a collaborative group of Data Scientists, Data Engineers, and Analysts, we develop statistical models, products and business rules necessary to analyze and continuously enhance our Product Catalog. We oversee the quality and correctness of all product components: titles, descriptions, images, and parameters. Our scope also covers ensuring consistency with sellers offers, automated product duplicate detection, building selection models and more. We work in close collaboration with developers and business teams, participating in the entire project lifecycle - from ideation through to implementation. Our ultimate goal is to create a single, reliable source of truth that powers a professional shopping experience for buyers and a fair, frictionless environment for partners. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN gross 14 600 - 20 825 Annual bonus based on your annual performance and company results. Our team is mostly based in Poznan and Warsaw. What will your job involve? Co-creating projects on each stage - from concept to productization - to deliver insights and models solving actual business problems Using a wide range of modeling techniques, including gradient boosting, Bayesian methods, causal inference, optimization, deep learning, and Generative AI (LLMs, Agentic AI) Working hand-in-hand with Data Engineers who support heavy data processing on GCP Working closely with Analysts, PMs, and Developers to ensure the solutions integrate seamlessly into broader initiatives Leveraging diverse data types, including spatial data, natural language (NLP), images, and time series Taking part in implementations of both offline and online models Engaging in brainstorming sessions, knowledge sharing, and continuous professional development Why should you work with us? Data Science plays a key role in the operation of the company - through the models and analyses provided you will have a significant impact on one of the largest eCommerce platforms in the world. You will have the possibility of developing AI tools from prototypes to large production solutions with real impact on users, merchants and employees. You will have access to huge data sets and the latest data processing technologies. You will have the opportunity to learn and use: Python (including various ML libraries), GCP environment (BigQuery, VertexAI, Cloud Composer, Dataflow), Airflow, PySpark, Gemini/GPT models. You will learn good programming, engineering and code management practices. You will be part of large-scale initiatives by proactively proposing and developing solutions. You’ll be a great fit if you bring: Hands-on Spark experience - experience working with Spark or PySpark with massive datasets. An MLOps & deployment mindset - experience building automated pipelines and deploying models into production environments. Solid software engineering habits - Python as primary language, writing clean, object-oriented code with unit tests and working with complex repositories. Strong Data Science foundations - deep understanding of statistics and machine learning, proper model selection and evaluation, accurate sample size calculation. Enthusiasm for GenAI & Agentic AI - theoretical and practical understanding of GenAI principles (prompting, validation) and effective use of coding assistants. Great communication & business sense - ability to translate business challenges into ML problems and explain technical results clearly. A relevant background - degree in a quantitative field (Mathematics, Physics, Computer Science, Economics) or equivalent hands-on experience in Data Science and Machine Learning roles. Bonus points: Experience with Apache Airflow for pipeline orchestration. What's in it for you: Flexible working hours in the hybrid model (4/1) and 30 days of occasional remote work. Long term discretionary incentive plan based on shares (restricted stock units). Annual bonus based on performance and company results. Well-equipped offices and modern work tools. MacBook Pro or corresponding Dell with Windows and necessary accessories. Cafeteria plan with medical, sports, lunch packages, insurance, purchase vouchers. English classes related to the job. Training budget, hackathons, internal learning platform. Additional day off for volunteering. Social events and team initiatives. Modern AI tools to automate repetitive tasks. Internal ecosystem based on self-service tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Large-scale environment including microservices architecture, open-source data bus, Service Mesh, petabytes of data, and production-used machine learning.

🏢 Summary: Technical role focused on designing and optimizing AI-driven backend systems for a conversational marketplace assistant, with strong emphasis on LLM orchestration, Retrieval-Augmented Generation, and semantic search. The position involves building and operating high-availability Python-based AI microservices integrated with Java/Kotlin services in a cloud-native environment. You will own end-to-end development of scalable, low-latency AI solutions leveraging modern ML and vector search technologies. 🗂️ Requirements: Proficiency in Python, Proficiency in Java, Proficiency in Kotlin, Experience with LLM orchestration, Experience with Retrieval-Augmented Generation (RAG), Experience with semantic search optimization, Ability to build and maintain microservices, Experience with cloud-native environments, Experience with vector databases and embedding models, English level B2 or higher 📃 Skills: Python, Java, Kotlin, Spring, LangChain, Langfuse, LLM, RAG, VectorSearch, Embeddings, Kubernetes, Docker, Consul, GitHub, GitHubActions, Microservices, SemanticSearch 🏢 Description: Software Engineer 2 (Python) Location: Poznań, PL, 61-569 Company: Allegro sp. z o.o. Team: Technology Contract Type: Employee About the job: Performance & Scale: Design, build, and optimize AI-driven systems that process complex natural language interactions. Delivering low-latency, high-quality responses from our AI Assistant requires high-availability and smart optimization of LLM and retrieval workloads in practice. Modern Tech Stack: Work with a world-class, cloud-native polyglot environment. Our core backend technologies include Java , Kotlin , Spring, and ADK . At the same time, our AI and orchestration layer heavily relies on Python . You will utilize Python and LangChain for complex LLM orchestration, alongside Langfuse for observability, prompt tracking, and evaluation. We leverage advanced vector search and modern ML solutions to make our assistant truly smart. True Ownership & Autonomy: We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your AI microservices and data pipelines, from design to deployment; and improvements are dictated by results of our own experiments and AI evaluation metrics. Complex Challenges: From LLM orchestration and Retrieval-Augmented Generation (RAG) to semantic search optimization, you'll tackle the complex backend problems that power a conversational marketplace assistant. You will work across the Java/Kotlin and Python ecosystems, integrating advanced embedding models, prompt pipelines, and vector databases to ensure our AI deeply understands and accurately retrieves information. In our domain, we focus on delivering the core search and retrieval capabilities for the Allegro AI Assistant. We maintain a critical entry point for users looking to discover products, compare offers, and get personalized recommendations through natural conversations. Striving for relevancy and accuracy first, we are designing, implementing, and operating an extensive system combining modern microservice architecture with Large Language Models, high-performance retrievers, and vast data sources. We care about data quality, robust context building, and near real-time accuracy to best guide users through a highly dynamic marketplace via an intelligent, conversational interface. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 14 200 - 20 200 Annual bonus based on your annual performance and company results. Our team is based in Poznań. We are looking for people who: Code in Python, Java and Kotlin ; Expect work that requires creative approach to search experience challenges, to be proud of enjoying its results together with all Allegro users; Want to create solid code, eagerly accept comments and share knowledge during code reviews; Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Know English at at least B2 level. Nice to have: You are open to diverse technologies and workflows, including dev-operational tools on one hand, and working with data on the other. Basic experience with LLM tuning (LoRA, PEFT), training and evaluation pipelines for models and/or basic frameworks for building AI Agents (Agent Development Kit, LangChain, AutoGen, CrewAI) would be great! What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Design and develop high-performance, cloud-native backend systems powering large-scale search and recommendation services. Work in an autonomous team owning microservices end-to-end in a distributed, real-time marketplace environment. Solve complex challenges in data streaming, search optimization, and machine learning at massive scale. 🗂️ Requirements: Proficiency in Kotlin or Java, Experience with backend development, Understanding of distributed systems, Experience with microservices architecture, Ability to design high-performance systems, English B2 level or higher, Participation in code reviews, Ownership of services from design to deployment 📃 Skills: Java, Kotlin, Spring, Kafka, Kubernetes, Vespa, Lucene, Solr, Docker, Consul, GitHub, GitHubActions, Microservices, DistributedSystems, MachineLearning, LLM, LoRA, PEFT, LangChain, AutoGen, CrewAI 🏢 Description: Senior Software Engineer (Java / Kotlin) Location: Poznań, PL, 61-569 Company: Allegro sp. z o.o. Team: Technology Contract Type: Employee About the job Massive Scale : Design, build, and optimize systems that handle thousands of requests per second. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. On the back side, there is Vespa and a highly optimized and heavily customized Lucene/Solr installation. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment; and improvements are dictated by results of our own experiments. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. And a constantly modernizing approach to search solutions will give you the opportunity to work with advanced embedding and ranking models and pipelines. In our domain we focus on delivering search results for multiple Allegro services, from search result pages, to recommendations, to offers comparisons in various placements. We maintain a critical entry point for users’ search experience through a huge catalog of products and offers, striving for relevancy first. To deliver, we are designing, implementing and operating an extensive system combining modern microservice architecture with high performance backends and vast data sources. We care about data quality and availability and strive for near real-time accuracy, to best guide users to products and offers in a highly dynamic marketplace. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 18 400 - 25 450 Annual bonus based on your annual performance and company results. Long term discretionary incentive plan based on Allegro.eu shares (restricted stock units). Our team is based in Poznań. We are looking for people who: Code in Kotlin or Java ; Expect work that requires creative approach to search experience challenges, to be proud of enjoying its results together with all Allegro users; Want to create solid code, eagerly accept comments and share knowledge during code reviews; Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Know English at at least B2 level. Nice to have: You are open to diverse technologies and workflows, including dev-operational tools on one hand, and working with data on the other. Basic experience with LLM tuning (LoRA, PEFT), training and evaluation pipelines for models and/or basic frameworks for building AI Agents (LangChain, AutoGen, CrewAI) would be great! What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Senior Software Engineer role focused on designing and optimizing high-availability, high-performance microservices in a cloud-native environment at massive scale. The position involves full ownership of backend services, working with Java/Kotlin, Big Data workflows, and distributed systems powering a real-time marketplace. You will build, deploy, and maintain scalable systems handling thousands of requests per minute. 🗂️ Requirements: Proficiency in Java or Kotlin, Willingness to work with Kotlin in production, Experience with microservices architecture, Experience with cloud environments, Knowledge of distributed systems, Experience with Big Data workflows, Ability to work with Airflow and BigQuery, Understanding of scalable and resilient system design, Ability to take end-to-end ownership of services, English level B2 or higher 📃 Skills: Java, Kotlin, Spring, MongoDB, Microservices, GCP, React, Airflow, BigQuery, Kubernetes, Docker, Consul, GitHub, GitHubActions 🏢 Description: Senior Software Engineer Location: Kraków, PL, 31-503 Company: Allegro sp. z o.o. Team: Technology Contract Type: Employee About the job Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment (GCP). Our core technologies include Java, Kotlin, Spring, MongoDB, microservices, React, Airflow (BigData). True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. About us We are the team behind Allegro Prices - one of our most important pricing programs. As part of the Competitive Price unit, we build its logic and grow its reach to keep our prices competitive. Our main goal is to ensure great deals on the products that shoppers actually look for. We do this at scale using full automation and data from many different sources Important things for you Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 9:30 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 18 400 - 25 450 Annual bonus based on your annual performance and company results. Our team is based in Kraków and Warsaw. We are looking for people who: Code in Kotlin or Java and are excited to master Kotlin in a production environment. Are open to diverse technologies , including Frontend. You don’t need to be a React master, but you’re ready to mentor Frontend engineers on architectural patterns and help build a truly cross-functional team. Want to grow into Big Data , learning how to handle large-scale datasets and build workflows with Airflow and BigQuery . Want to be proud of the code they create ; they value high-quality code reviews and engage in substantive discussions on software engineering best practices; Feel comfortable interacting with stakeholders and taking full end-to-end ownership of initiatives - from initial requirements gathering through implementation to post-deployment monitoring; Have a solid foundation in microservices architecture and feel at home working in cloud environments , understanding how to build scalable and resilient systems; Know English at at least B2 level. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: The offer is for a Software Engineer 1 (Python) role within the Observability & Monitoring team, focused on building and maintaining backend tools that monitor system health and ensure service reliability. The position involves developing on-call tooling, supporting distributed systems, and working within a large-scale microservices environment. It provides a hybrid work model, performance-based bonus, and access to modern DevOps and AI-supported development tools. 🗂️ Requirements: Proficiency in Python, Basic understanding of distributed systems, Knowledge of Kubernetes, Willingness to work with TypeScript and frontend technologies, Product-oriented mindset, Responsibility for system reliability, English proficiency at C1 level 📃 Skills: Python, Kubernetes, TypeScript, Docker, Consul, GitHub, GitHubActions, Hermes, ServiceMesh, AI 🏢 Description: About the Job You will join the Observability & Monitoring team, which is a vital part of the technical platform. The team focuses on building and maintaining backbone tools that monitor and analyze the health of services. When a service or application fails or returns errors, the systems process that information and notify the right people. In this role, you will help ensure system reliability and support and develop on-call tooling that provides 24/7 technical support across the company. Important Information Flexible working hours in a hybrid model (4/1) – working hours start between 7:00 a.m. and 10:00 a.m. There are also 30 days of occasional remote work. Salary range (contract of employment, tax-deductible cost): PLN 11 200 - 15 250. Annual bonus based on annual performance and company results. Requirements - Coding in Python and building backend solutions - Basic understanding of distributed systems - Knowledge of Kubernetes and application interactions - Willingness to work with TypeScript and frontend technologies (nice to have) - Product-oriented mindset and interest in system architecture - Taking responsibility for reliability of critical monitoring systems - English at minimum C1 level Technology Environment Internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Work in a large-scale environment including over 1000 microservices, an open-source data bus (Hermes) handling 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. Use of modern AI tools to automate repetitive tasks and support development. Benefits Well-equipped offices and modern work tools. Choice of 16" or 14" MacBook Pro or corresponding Dell with Windows and necessary accessories. Cafeteria plan with medical, sports, lunch packages, insurance, and vouchers. Paid English classes related to job needs. Training budget, hackathons, internal learning platform, and inter-team initiatives. Additional day off for volunteering. Social events and internal tech initiatives.

🏢 Summary: Backend Engineer role focused on developing and maintaining public APIs for creating products and offers, using Java/Kotlin and integrating Generative AI workflows. The position involves building robust backend systems at scale, ensuring code quality, and contributing to architectural decisions within a microservices ecosystem. 🗂️ Requirements: Proficiency in Java and/or Kotlin, Willingness to work with Generative AI workflows, Experience in backend development, Ability to work with microservices architecture, Knowledge of code quality, testing, and architectural standards, English B2 level, Polish B2 level 📃 Skills: Java, Kotlin, GenAI, Kubernetes, Docker, Consul, GitHub, GitHubActions, Microservices, REST, API, Hermes, ServiceMesh, MachineLearning 🏢 Description: The team you will be joining manages the public APIs responsible for creating new products and offers on Allegro. Their core mission is to streamline this process for the broadest possible range of partners. To achieve this, they develop robust backend systems and integrate Generative AI workflows to ensure effortless offer management. Important things for you Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work; The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): 10 700 - 14 900PLN gross Annual bonus (depending on your annual assessment and the company's results) Our team is based in Poznań We are looking for people who: Code in Java and/or Kotlin. Are willing to work with GenAI workflows. Expect work that has a deeper meaning (not only tasks "management has commissioned") and want to enjoy its results. Want to be proud of the code they create. Eagerly accept comments and share knowledge during code reviews. Can look for effective solutions to the requirements set by users. Want to constantly develop and update their knowledge. Know English and Polish at B2 level. Your responsibilities: Executing well-defined tasks with medium complexity within the scope of team projects. Completing tasks based on predefined priority levels. Understanding the user and their perspective to inform development decisions. Using semantic code and learn the basics of accessibility to avoid common barriers for users with disabilities. Conducting off-hours duty on team products - possible via joint employee's and manager's decisions. Taking responsibility and ownership for developed features. Proposing and implementing solutions to engineering challenges. Seeking assistance from teammates when needed to overcome technical obstacles. Making decisions about code constructs and consulting with the team on architectural issues. Suggesting design process improvements to enhance product quality. Identifying logical errors in the codebase and proposing actionable improvements. Defining and reporting technical debt to ensure long-term quality at the code and architecture levels. Actively acquiring and applying product domain knowledge during development. Considering the impact of work on other domains to ensure system-wide consistency. Building a solid foundation in the chosen technology stack. Learning new technologies and apply the acquired knowledge effectively in projects. Meeting quality standards including code readability, testing, architecture, stability, and monitoring. Focusing on mastering and working within a single core technology. Occasionally providing constructive feedback. Incorporating received feedback into ongoing work and professional development. Collaborating and communicate effectively with others using facts and data. Engaging in self-development and pursuing growth within well-defined professional areas. Occasionally sharing knowledge with the team or individual colleagues. What's in it for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. Annual bonus based on your annual performance and company results. Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Backend Software Engineer role focused on developing and optimizing Product Catalog solutions, particularly duplicate detection and product grouping at scale. The position involves designing and maintaining backend services and architectures in a cloud-based, microservices environment using Kotlin and JVM technologies. You will work on high-scale systems, contributing to core platform components and automation. 🗂️ Requirements: Commercial experience in Kotlin development, Strong knowledge of backend architectural patterns, Experience designing and maintaining backend services and APIs, Ability to design software architectures, Experience with debugging and resolving software defects, Fluent Polish (C1), English proficiency (B2), Experience working with distributed systems at scale 📃 Skills: Kotlin, JVM, Kubernetes, Docker, Consul, GitHub, GitHubActions, Microservices, APIs, Cloud, Hermes, ServiceMesh 🏢 Description: About the job In this role, you will be a key player in evolving our Product Catalog - the foundational pillar of our platform. Your primary objective will be to build and optimize solutions for duplicate detection and accurate product grouping across a broad portfolio of system components. Your work will directly shape the daily experience of our users. You will ensure Buyers enjoy a high-quality, clutter-free shopping experience, while helping Partners list their products more efficiently. Expect to tackle exciting technical challenges at scale, working with a diverse tech stack that includes online JVM services and offline processing in a public-cloud environment. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN gross 14 600 - 20 825 Annual bonus based on your annual performance and company results. Our team is based in Toruń. What You'll Do: Design, develop, test and maintain high-quality code for backend services, APIs and automation scripts. Debug and resolve software defects and issues. Design and develop new project architectures while proposing better architectural approaches for existing solutions. Share knowledge with team members and support junior engineers. Collaborate with product managers, data analysts, UX designers and fellow engineers to gather and refine requirements. Support on-call engineers by participating in the Software Engineer role on-call rotation. Write clean, efficient  and well-documented code. We are looking for someone who has: Solid commercial experience in Kotlin development and a strong command of backend architectural patterns. Language proficiency in Polish at a C1 level and English at a B2 level. Excellent problem-solving and decision-making skills, paired with a Data-Driven mindset. High learning agility, adaptability to change, flexibility  and strong skills in communication and cooperation. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism (see more here), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here. #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale, which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Backend engineering role focused on designing and operating high-availability microservices at massive scale within a cloud-native environment. The position involves building AI-driven pipelines and distributed systems that ensure product catalog quality in a real-time marketplace. You will own services end-to-end, working with Kotlin/Java, streaming technologies, and Kubernetes in an autonomous, agile team. 🗂️ Requirements: Proficiency in Kotlin or Java, Experience with distributed systems and microservices architecture, Experience with data streaming systems, Ability to design high-availability and high-performance systems, Experience with cloud-native environments, English B2 level minimum, Polish B2 level minimum 📃 Skills: Kotlin, Java, Spring, Kafka, Kubernetes, Docker, Consul, GitHub, GitHubActions, Microservices, LLM, MachineLearning 🏢 Description: About the job: Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. Our team owns the quality of product content in Allegro's product catalog — names, descriptions, and the processes that keep them correct at scale. We build AI-driven pipelines (including LLM-based evaluation and generation) that automatically maintain content quality, and we run A/B experiments to prove when catalog data is ready to replace merchant-provided content on the buyer path. We work in a cross-functional setup with backend engineers, a product manager, and close collaboration with data analysts and quality specialists. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 11 200 - 15 250 Annual bonus based on your annual performance and company results. Our team is based in Toruń. We are looking for people who: Code in Kotlin or Java ; Expect work that has a deeper meaning (not only tasks "management has commissioned") and want to enjoy its results; Want to be proud of the code they create. They eagerly accept comments and share knowledge during code reviews; Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Are proactive and positive — you'll join people who actually like collaborating; Know English and Polish at at least B2 level. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Backend Engineer role focused on building and operating high-availability, high-performance microservices in a large-scale, real-time marketplace. The position involves designing distributed systems, data streaming solutions, and AI-driven content quality pipelines using a modern cloud-native stack. You will own services end-to-end in an autonomous team following a "you build it, you run it" approach. 🗂️ Requirements: Proficiency in Kotlin or Java, Experience building high-availability, high-performance backend systems, Experience with distributed systems and microservices architecture, Experience with data streaming systems, Experience working in cloud-native environments, Ability to design, deploy, and operate services in production, Experience with AI/ML-driven pipelines, English B2 level minimum, Polish B2 level minimum 📃 Skills: Kotlin, Java, Spring, Kafka, Kubernetes, Docker, Consul, GitHub, GitHubActions, Microservices, DistributedSystems, DataStreaming, MachineLearning, LLM, A/BTesting, ServiceMesh, Cloud, Hermes 🏢 Description: About the job: Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. Our team owns the quality of product content in Allegro's product catalog — names, descriptions, and the processes that keep them correct at scale. We build AI-driven pipelines (including LLM-based evaluation and generation) that automatically maintain content quality, and we run A/B experiments to prove when catalog data is ready to replace merchant-provided content on the buyer path. We work in a cross-functional setup with backend engineers, a product manager, and close collaboration with data analysts and quality specialists. Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 11 200 - 15 250 Annual bonus based on your annual performance and company results. Our team is based in Toruń. We are looking for people who: Code in Kotlin or Java ; Expect work that has a deeper meaning (not only tasks "management has commissioned") and want to enjoy its results; Want to be proud of the code they create. They eagerly accept comments and share knowledge during code reviews; Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Are proactive and positive — you'll join people who actually like collaborating; Know English and Polish at at least B2 level. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: Backend engineering role in the Recommendation team focused on building and operating high-scale, high-availability microservices and ML-serving infrastructure in a cloud-native environment. The position involves designing distributed systems, data streaming solutions, and end-to-end ML systems that power real-time personalized recommendations. You will own services from design to deployment using modern technologies such as Kotlin, Spring, Kafka, Kubernetes, BigQuery, and Spark. 🗂️ Requirements: Proficiency in Kotlin or Java, Willingness to develop in Kotlin on greenfield projects, Experience with distributed systems and microservices architecture, Experience with cloud-native technologies and containerization, Ability to design high-availability and high-performance systems, Experience with data processing or data streaming systems, Understanding of ML model serving concepts, Experience with BigQuery or Apache Spark for data processing, English proficiency at B2 level or higher 📃 Skills: Kotlin, Java, Spring, Kafka, Kubernetes, Docker, Consul, GitHub, GitHubActions, BigQuery, Spark, Python, VectorSearch, Microservices, ML, Hermes 🏢 Description: About the job Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. End-to-End ML Systems: Bridge the gap between big data and real-time product impact. You’ll build the infrastructure for serving ML models , using BigQuery and Apache Spark for offline data processing and Vector Search databases for high-speed retrieval. You’ll integrate these components with our microservices architecture to create the sophisticated recommendation systems that power a personalized user experience. Join the Recommendation team! You will have a chance to build tools for recommendations on Allegro - one of the most visible products on the platform. Your team works closely with the Machine Learning team, creating the best experience for customers. High performance, engineering best practices and great atmosphere in the team guaranteed! Important things for you Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 11 200 - 15 250 Annual bonus based on your annual performance and company results. Our team is based in Warsaw. We are looking for people who Code in Kotlin or Java and are eager to master Kotlin by taking part greenfield project Want to be proud of the code they create ; they value high-quality code reviews and engage in substantive discussions on software engineering best practices; Are excited about building new products and want to experience the journey of launching a fresh project within the Allegro ecosystem; Are open to developing soft skills and exploring a full-stack mindset by learning new backend, frontend, and mobile technologies; Are open to incorporating AI coding assistants into their daily work to maximize efficiency and focus on complex problem-solving Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Know English at at least B2 level; Are eager to dive into the world of ML Engineering , learning how to serve ML models (using Python) and handle large-scale offline data processing using tools like BigQuery or Apache Spark. What's in it for you Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!