👉Java Developer

🏢 Summary: The role involves developing and maintaining high-performance backend systems for advertising and e-commerce platforms, focusing on scalable microservices and real-time data processing using Kotlin and Spring Boot. You will design low-latency services, contribute to system architecture, and support production environments in a high-scale setting. The position also emphasizes AI-assisted development practices and collaboration within engineering teams. 🗂️ Requirements: 3+ years of backend development experience, Very good knowledge of Kotlin, Very good knowledge of Spring Boot, Hands-on experience with microservices architecture, Experience with NoSQL databases, Experience with MongoDB, Experience building and maintaining backend systems and APIs, Understanding of system design and scalable architecture, Experience with high-performance and high-scale systems, English B2 level, Polish C1 level, Work permit in the European Union, Openness to occasional visits to Warsaw office, Experience using AI-powered coding assistants 📃 Skills: Kotlin, SpringBoot, MongoDB, NoSQL, Microservices, REST, APIs, GenAI, Claude, GitHubCopilot, Cursor, AWS, Azure 🏢 Description: 🟣 You will be: developing and maintaining backend systems for advertising and e-commerce platforms, building low-latency, high-performance services processing large volumes of data, developing scalable microservices and APIs using Kotlin and Spring Boot, working on real-time event processing and advertising targeting mechanisms, contributing to architecture design and system scalability improvements, collaborating with stakeholders and supporting engineering best practices, including code reviews and code quality standards, participating in technical readiness/on-call support for production incidents a few days per month. 🟣 Your profile: 3+ years of professional experience in backend development, very good knowledge of Kotlin and Spring Boot, openness to occasional visits to the Warsaw office (1–2 days per quarter), hands-on experience with microservices architecture, practical experience working with NoSQL databases, especially MongoDB, experience building and maintaining backend systems and APIs, understanding of system design and scalable architecture principles, experience working with high-performance and high-scale systems, strong analytical thinking and problem-solving skills, ability to collaborate effectively with stakeholders and engineering teams, good communication skills in English (B2) and Polish (C1), practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery. Work from the European Union region and a work permit are required. 🟣 Nice to have: experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, multiSport card - we subsidise a MultiSport card, mental Health Support. 🤸‍♂️ We are flexible: B2B or employment contract, contract for an indefinite period.

🏢 Summary: Backend Java Developer role focused on building and maintaining high-performance, scalable systems for transaction, payment, and cashier functionalities within a complex trading platform. The position involves developing RESTful and RPC APIs, handling high-concurrency and large-scale data processing in distributed environments, and integrating with third-party services. The role requires strong production troubleshooting skills and collaboration within cross-functional teams. 🗂️ Requirements: 5+ years of Java backend development experience, Strong experience with Java 8+, Strong experience with Spring Boot, Experience in fintech product development, Experience with B2B systems, Hands-on experience with high-concurrency and multi-threaded environments, Experience with high-volume traffic systems, Experience with large-scale data processing, Knowledge of MyBatis, Redis, and message queues, Experience with MySQL and complex query optimization, Experience with Elasticsearch, Experience with Hadoop or big data technologies, Experience with event-driven architectures, Experience with unit and integration testing, Experience integrating third-party APIs, Understanding of distributed systems and microservices, EU work permit and EU-based work availability 📃 Skills: Java, Spring, SpringBoot, MyBatis, Redis, MySQL, Elasticsearch, Hadoop, Dubbo, REST, RPC, SQL, Multithreading, Microservices, Kafka, RabbitMQ 🏢 Description: 🟣 You will be: designing, developing, and maintaining high-performance backend systems using Java and Spring Boot, working on transaction, payment, and cashier-related functionalities within a complex trading platform, building and maintaining RESTful and RPC APIs (e.g. using Apache Dubbo), developing solutions capable of handling high-volume traffic, high concurrency, and multi-threaded environments, processing and optimizing large volumes of data within distributed systems, collaborating with cross-functional teams to deliver scalable and reliable systems, integrating backend services with third-party applications and external systems, troubleshooting, debugging, and optimizing system performance in production environments. 🟣 Your profile: 5+ years of professional experience in Java backend development, strong experience with Java (8+) and Spring Boot, experience in business product development within fintech environments, experience working on B2B products, hands-on experience with high-concurrency systems, multi-threading, and high-volume traffic environments, proven experience working with large-scale data processing systems, solid knowledge of technologies such as MyBatis, Redis, and message queue systems, experience working with relational databases such as MySQL, including writing complex queries and performance tuning, experience working with Elasticsearch and big data technologies such as Hadoop, experience with messaging systems (queues) and event-driven architectures, experience with unit and integration testing, experience integrating with third-party services and APIs, strong debugging and problem-solving skills, solid understanding of software design patterns and backend architectures, practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery, good communication skills and ability to work in a team environment, immediate availability or a short notice period is preferred. Work from the European Union region and a work permit are required. 🟣 Nice to have: familiarity with RPC frameworks such as Apache Dubbo, experience working with systems serving large-scale user bases, understanding of distributed systems and microservices architecture, experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, multiSport card - we subsidise a MultiSport card, mental Health Support. 🤸‍♂️ We are flexible: B2B or employment contract, contract for an indefinite period.

🏢 Summary: Senior Fullstack Engineer role focused on building intelligent advertising systems using React and Kotlin, including ML-driven recommendation engines and automated campaign management tools. The position involves developing scalable, event-driven cloud architectures and high-performance APIs for analytical platforms within a GCP environment. Hybrid work model in Warsaw with strong emphasis on modern microservices and microfrontend architectures. 🗂️ Requirements: Minimum 3 years of full-stack development experience, Strong experience with React and Kotlin, Proficiency in TypeScript, HTML, CSS, Experience with Spring Boot and microservices architecture, Experience with GCP cloud environment, Experience with MongoDB and SQL databases, Understanding of event-driven architectures and large-scale data processing, Experience with testing frameworks such as Jest, Vitest, or Playwright, Communicative Polish and English, Legal right to work in the European Union 📃 Skills: Kotlin, React, TypeScript, HTML, CSS, SpringBoot, MongoDB, SQL, GCP, Microservices, Microfrontends, Jest, Vitest, Playwright, APIs, SSR, Accessibility, EventDriven 🏢 Description: Unleash innovation — design the future of intelligent advertising ecosystems! Warszawa-based opportunity with hybrid work model. As a Senior Fullstack Engineer – React and Kotlin Specialists , you will be working for our client, a leader in building advanced advertising tools, focusing on creating intelligent recommendation systems and automating campaign management for advertisers on Allegro Ads. Join a mission-driven project that revolutionizes how businesses grow through cutting-edge technology and data-driven insights, offering exciting avenues for professional growth and innovation. Your main responsibilities: Develop and maintain backend services using Kotlin, integrating machine learning-driven recommendation engines in collaboration with data science teams. Build scalable, event-driven architectures to process large data volumes within cloud environments, leveraging GCP. Design and implement high-performance APIs to support analytical dashboards and market benchmarks. Create and optimize scalable microfrontends using React, prioritizing accessibility and server-side rendering for analytical tools. Collaborate with cross-functional teams to deliver seamless, secure, and efficient software solutions. Ensure high code quality through testing frameworks such as Jest, Vitest, or Playwright, with a focus on performance and reliability. Contribute to evolving microservice architectures, utilizing Spring Boot, MongoDB, SQL, and cloud-native tools. Participate actively in code reviews, sprint planning, and technical discussions to foster continuous improvement. You're ideal for this role if you have: At least 3 years of experience in full-stack development, with a focus on React and Kotlin. Strong proficiency in TypeScript, React, HTML/CSS, and backend technologies like Kotlin, Spring Boot, and microservices. Experience working with cloud ecosystems, preferably GCP. Solid understanding of database management, including MongoDB and SQL. Familiarity with event-driven architectures and large-scale data processing. Ability to communicate effectively in Polish and English. Experience working in an Agile environment with a focus on delivering high-quality software. It is a strong plus if you have: (optional) Certifications related to GCP or microservices architecture. Experience with agentic coding tools like Copilot/OpenCode. Knowledge of accessibility standards (a11y) and performance optimization techniques. Language Required for the role: Polish (Communicative) English (Communicative) Eligibility for this role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Backend Developer role focused on designing, building, and maintaining scalable Java and Kotlin-based applications and microservices within an international team. The position involves developing high-quality backend systems, collaborating with cross-functional teams, and optimizing distributed systems performance. The role emphasizes clean code, modern frameworks, and agile delivery practices. 🗂️ Requirements: 5+ years of backend development experience with Java 8+ and Kotlin, Strong knowledge of Spring Framework and Spring Boot, Experience building RESTful APIs and microservices, Experience with SQL and NoSQL databases, Understanding of Agile/Scrum methodologies 📃 Skills: Java, Kotlin, Spring, SpringBoot, REST, Microservices, SQL, NoSQL, PostgreSQL, MongoDB, Agile, Scrum 🏢 Description: We are looking for skilled Java & Kotlin Developers to join our growing technology team in Poland. As part of an international development group, you’ll design, build, and maintain scalable backend systems using Java and modern frameworks. You’ll collaborate closely with cross-functional teams to deliver high-quality, reliable, and efficient software solutions. Key Responsibilities Design, develop, and maintain Java-based applications and microservices. Write clean, efficient, and testable code following best practices and coding standards. Collaborate with front-end developers , DevOps engineers , and QA teams to ensure seamless integration and delivery. Participate in code reviews , architecture discussions, and agile ceremonies. Contribute to technical documentation and continuous improvement of development processes. Troubleshoot and optimize performance across distributed systems. Requirements 5+ years of experience in backend development using Java 8+ Kotlin . Strong understanding of Spring Framework / Spring Boot . Experience with RESTful APIs , microservices , and SQL / NoSQL databases (e.g., PostgreSQL, MongoDB). Knowledge of Agile / Scrum methodologies. Good command of English (B2 or higher) – Polish language skills are a plus. Nice to Have Experience with cloud platforms (AWS, Azure, or GCP). Familiarity with message brokers (Kafka, RabbitMQ). Knowledge of unit testing and test automation frameworks (JUnit, Mockito). Interest in DevOps or system design concepts. How to Apply If you’re passionate about building high-quality Java applications and want to be part of a dynamic engineering team, send your CV

🏢 Summary: The offer is for a DevOps Engineer responsible for building and supporting tools, processes, and infrastructure that enable fast, reliable, and scalable software delivery. The role focuses on CI/CD, cloud infrastructure, container orchestration, observability, and integrating AI-powered tools into the software development lifecycle. It involves ensuring high availability, automation, and operational insight across AWS-based environments. 🗂️ Requirements: 3+ years of experience with DevOps practices and Continuous Delivery, Practical experience with AI-powered development assistants, Hands-on experience with AWS services and networking, Experience with Kubernetes and container orchestration, Knowledge of Python, Experience with GitOps practices, Experience with CI/CD pipelines and tooling, Experience with monitoring, logging, and observability tools, Knowledge of Terraform and Helm, Proficiency in Bash and PowerShell scripting, Knowledge of API management tools, Security awareness (OWASP, encryption, secrets management), Upper intermediate/advanced English (B2/C1), Work permit and residence in the EU 📃 Skills: AWS, Kubernetes, EKS, Python, GitOps, ArgoCD, Terraform, Helm, Bash, PowerShell, GitLab, GitHub, CI/CD, Prometheus, Grafana, AppDynamics, OpenSearch, Apigee, Tyk, Kiro, OWASP, Encryption 🏢 Description: 🟣 You will be: building and supporting the tools, processes and infrastructure empowering the faster delivery and scaling of software iterations (ideally with greater quality and the necessary operational insight), ensuring availability, reliability and scalability of application infrastructure, building and supporting continuous integration/delivery and release tools, ensuring the right metrics are collected and monitored. 🟣 Your profile: mart and tech-savvy engineer with 3+ years of experience working with DevOps practices and Continuous Delivery, practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery, practical knowledge of AWS services, infrastructure and networking, working experience with Kiro, practical knowledge of Tyk, proficiency in Google Cloud Apigee, experience with Kubernetes (ideally EKS on AWS) and container orchestration, Python knowledge, hands-on with GitOps practices, preferably with ArgoCD, medium skills in Terraform and Helm, proficiency in Bash and PowerShell scripting, experience with CI/CD pipelines and tooling (GitLab CI/CD, GitHub Actions, or similar), experience with monitoring, observability, and logging tools, such as Prometheus, Grafana, AppDynamics, and OpenSearch, security awareness (OWASP, encryption, secrets management), very communicative and collaborative, with a strong sense of ownership, upper intermediate/advanced English (B2/C1). Work from the European Union region and a work permit are required. 🟣 Nice to have: Experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work. Interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR Interview – Technical Interview - Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, MultiSport card - we subsidise a MultiSport card, mental Health Support.

🏢 Summary: Backend Developer role focused on modernizing and optimizing backend services and data pipelines, including technology upgrades, authentication migration, and automation initiatives. The position involves working with Java/Scala ecosystems, Spark pipelines, and OAuth-based security in a hybrid model with onboarding in Sweden. B2B contract with competitive hourly rate and English as the project language. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Familiarity with Play Framework internals, Experience with Spark for data pipelines, Experience with OAuth-based authentication patterns, Availability for hybrid work (3 days/week in Warsaw or Cracow), Availability for 2-week onboarding in Malmo, Sweden, Fluent English 📃 Skills: Java, Scala, Play, Spark, OAuth, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw OR Cracow office. ⏳ Duration : > 3 months contracts . 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : August 3rd at the latest. 📝 Contract : B2B > up 200 zl/h. ⚙️ Recruitment process : 2 meetings. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Hands-on Tech Lead role focused on designing and delivering scalable backend platforms and RESTful microservices for a global e-commerce and wellness technology ecosystem. The position involves technical leadership, backend development with Kotlin/Java and Spring Boot, mentoring engineers, and driving architecture decisions in a cloud-native environment. The role offers a hybrid work model in Warsaw with a competitive salary and benefits. 🗂️ Requirements: 6+ years of software development experience, Backend development experience with Java or Kotlin, Experience building and scaling RESTful microservices, Hands-on experience with Spring Boot, Hands-on experience with Docker, Hands-on experience with Kubernetes, Experience with AWS or GCP, Experience with PostgreSQL, MongoDB, DynamoDB, or Elasticsearch, Experience with unit testing and test-driven development, Experience with CI/CD pipelines, Experience leading technical projects and mentoring engineers, Ability to guide architecture decisions and delivery planning, Experience working in agile cross-functional teams 📃 Skills: Kotlin, Java, Spring, SpringBoot, Microservices, Docker, Kubernetes, AWS, GCP, PostgreSQL, MongoDB, DynamoDB, Elasticsearch, CI/CD, Datadog, REST, TDD, DevOps, Agile 🏢 Description: We are looking for a Kotlin/Java Tech Lead to join an e-commerce engineering team. In this role, you will lead the design and delivery of scalable backend platforms and services powering the company's customer-facing commerce experience across web, retail, and other sales channels. This is a hands-on technical leadership role. You will guide engineering decisions, mentor other engineers, partner closely with product and design, and help the team deliver high-impact initiatives with strong engineering quality, scalability, and reliability. Key takeaways: - Stack: Kotlin/Java, Spring Boot, microservices, Docker, Kubernetes, AWS, PostgreSQL, CI/CD, Datadog, technical leadership experience - Salary: 26 000 PLN - 30 000 PLN gross on the Contract of Employment - Working model: Hybrid - 3 days/week from the office Recruitment process: - A call with recruiter - Panel interviews with the team (coding, architecture, and cross-collaboration interviews) Responsibilities: Technical Leadership - Lead the delivery of small to large engineering initiatives, from technical discovery through implementation and production readiness. - Guide the team in making strategic backend architecture decisions that support scalability, performance, and long-term maintainability. - Own technical trade-offs and ensure solutions are aligned with business goals, user needs, and engineering standards. - Mentor engineers through design reviews, code reviews, and day-to-day technical collaboration. Backend Engineering - Build and improve backend platforms and services. - Design and scale RESTful microservices used across web, retail, and other sales channels. - Develop backend services using technologies such as Java, Kotlin, Spring Boot, Docker, and Kubernetes. - Work with data stores such as PostgreSQL, MongoDB, DynamoDB, Elasticsearch, or similar technologies. Delivery & Product Collaboration - Partner closely with product managers, designers, and peer engineers to scope, build, and deliver end-to-end features. - Translate product strategy and business requirements into reliable, scalable technical solutions. - Drive iterative delivery in an agile engineering environment. - Maintain strong relationships with stakeholders and ensure clear communication around scope, risks, and delivery progress. Engineering Excellence - Promote strong engineering practices, including unit testing, test-driven development, CI/CD, observability, and production ownership. - Apply a DevOps mindset to build services that are reliable, observable, and easy to operate. Requirements: Technical Expertise - 6+ years of professional software development experience. - Strong backend engineering experience with Java or Kotlin. - Proven experience building and scaling RESTful microservices. - Hands-on experience with Spring Boot, Docker, and Kubernetes. - Experience with cloud infrastructure such as AWS or GCP. - Familiarity with data stores such as PostgreSQL, MongoDB, DynamoDB, Elasticsearch, or similar technologies. - Experience with unit testing, test-driven development, and CI/CD pipelines. Leadership Experience - Experience leading engineers to deliver high-impact technical projects. - Proven ability to mentor junior and mid-level engineers and support their technical growth. - Ability to guide technical decision-making, architecture discussions, and delivery planning. - Experience with end-to-end feature ownership in a cross-functional product environment. Collaboration & Mindset - Strong communication skills and ability to work effectively with product, design, and engineering stakeholders. - Agile mindset with a strong focus on iterative design and delivery. - High ownership, strong delivery orientation, and ability to operate in a fast-moving engineering environment. - Strong desire to learn, share knowledge, and help engineers achieve their highest potential. What we offer: - 100% paid medical care - Multisport - Creative tax (KUP) - Home office allowance - MacBook Pro If you enjoy technical leadership, hands-on backend engineering, and building platforms used at scale, this role is a strong opportunity to make a real impact. Please apply via the careers page and submit your CV in English.

🏢 Summary: Senior Magento 2 / Adobe Commerce Backend Developer role focused on building and maintaining scalable e-commerce solutions. The position involves developing custom modules, integrating external services, optimizing performance, and ensuring high code quality in an agile environment. The role also includes working with APIs, message queues, and cloud-based infrastructure to support reliable commerce platforms. 🗂️ Requirements: 7+ years commercial experience with Magento 2 / Adobe Commerce backend, Strong knowledge of Magento architecture, modules, and customization, Proficiency in PHP (OOP, MVC), Strong knowledge of MySQL, Hands-on experience with REST and GraphQL APIs, Experience with message queues (RabbitMQ), Experience integrating payment gateways and logistics systems, Experience with Elasticsearch, Familiarity with monitoring tools, Knowledge of DevOps practices and Adobe Cloud, Ability to perform code reviews and ensure code quality, Experience working in Agile environment, Very good English (min. B2), Work authorization in the EU 📃 Skills: Magento, AdobeCommerce, PHP, MySQL, REST, GraphQL, RabbitMQ, Elasticsearch, NewRelic, Datadog, SumoLogic, CloudFront, Cloudflare, DevOps, AdobeCloud, AI, Claude, Copilot, Cursor 🏢 Description: 🟣 You will be: developing and maintaining backend solutions based on Magento 2 / Adobe Commerce, designing and implementing custom modules, integrations, and platform enhancements, working with APIs (REST, GraphQL) and integrating external services (payments, logistics, booking systems), ensuring high code quality through code reviews and best engineering practices, collaborating with cross-functional teams in an agile environment, supporting performance optimization, monitoring, and reliability of e-commerce platforms. 🟣 Your profile: 7+ years of commercial experience with Magento 2 / Adobe Commerce backend development, very good understanding of Magento architecture, modules, and customization best practices, solid knowledge of PHP (OOP, MVC) and MySQL, hands-on experience with Magento APIs (REST, GraphQL) and message queues (e.g. RabbitMQ), experience integrating external services such as payment gateways and logistics systems, familiarity with Elasticsearch and monitoring tools (e.g. New Relic, Datadog, Sumo Logic), experience working with CDN services (e.g. CloudFront, Cloudflare), understanding of Agile methodologies, competence in performing code reviews (PRs) with a strong focus on code quality and best practices, along with good knowledge of DevOps and Adobe cloud management, practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery, strong communication skills and ability to work in a collaborative environment, very good command of English (min. B2), availability to start as soon as possible (or within a short notice period). Work from the European Union region and a work permit are required. 🟣 Nice to have: familiarity with CI/CD pipelines (e.g. GitHub, CircleCI) and external booking systems, knowledge of analytics tools (e.g. Google Analytics, Google Tag Manager) and A/B testing solutions, experience with consent management tools (e.g. OneTrust), expertise in performance optimization and scalable e-commerce solutions, experience with React, Knockout.js, jQuery, familiarity with tools such as Vertex AI, CAPTCHA solutions, or review platforms (e.g. Trustpilot), experience working with multi-vendor e-commerce setups or marketing tools (e.g. Klaviyo), experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, multiSport card - we subsidise a MultiSport card, mental Health Support.

🏢 Summary: Backend Engineer role in the Advertising team focused on building and operating high-scale, cloud-native systems and end-to-end ML infrastructure for a real-time marketplace. The position involves developing microservices, data pipelines, and advertising systems using Kotlin/Scala, Spring, Kafka, and big data technologies. You will own services end-to-end in a high-availability environment handling massive traffic and complex distributed challenges. 🗂️ Requirements: Proficiency in Kotlin or Scala, Experience with Spring Boot, Experience with Kafka, Hands-on experience with Apache Airflow, Hands-on experience with Apache Spark, Proficiency in PostgreSQL, Experience with database migrations, Experience designing and integrating APIs, English level B2 or higher 📃 Skills: Kotlin, Scala, Spring, SpringBoot, Kafka, Airflow, Spark, PostgreSQL, BigQuery, Kubernetes, Docker, Consul, GitHub, GitHubActions, React, TypeScript 🏢 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 using BigQuery and Apache Spark for offline data processing. You’ll integrate these components with our microservices architecture to create the sophisticated advertising system that powers a personalized user experience. Join the Advertising team! You will have a chance to build Allegro Ads - 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 18 850 - 25 900 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 Scala and have experience with Spring Boot and Kafka to build robust backend systems; Have hands-on experience with Apache Airflow and Spark , enabling them to manage high-velocity data pipelines and build scalable reporting engines; Are proficient in PostgreSQL and have experience with database migrations and designing integrations via APIs; Enjoy close collaboration with Data Scientists and Analysts, working together to implement complex models and turn raw data into actionable insights; Are enthusiastic about AI and want to stay at the forefront of technical innovation; Want to build impactful tools for a diverse range of users, helping them understand campaign performance through advanced statistics and dashboards; Experience with frontend technologies (React/TypeScript) is a “Nice to have” to help build modern frontend reporting components; Are excited to join a growing team where they can influence the technical vision and help shape new projects from the ground up within the ecosystem; 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: Remote Java Developer role focused on building and maintaining highly scalable backend services for advertising campaign management, including budgeting and billing domains. The position involves designing high-availability, horizontally scalable solutions within a cross-functional team and collaborating directly with product stakeholders. Opportunity to work in a cloud-based, distributed environment supporting large-scale, data-intensive systems. 🗂️ Requirements: Commercial experience in Java or Kotlin, Experience with Spring Boot, Knowledge of object-oriented programming and design patterns, Understanding of microservices architecture and distributed systems, Experience with PostgreSQL, Basic knowledge of MongoDB, Understanding of asynchronous and event-driven systems, Experience with REST APIs and service integration, Ability to work in cloud-based environments 📃 Skills: Java, Kotlin, Spring, SpringBoot, MongoDB, PostgreSQL, Kafka, Microservices, REST, Git, CI/CD, GoogleCloud, BigQuery 🏢 Description: Salary: 600 - 1000 PLN / dzień Remote work Why choose this offer? Real impact on system architecture Opportunity to design solutions with high availability and horizontal scalability Collaboration within a mature, cross-functional team Direct communication with Product Owners and non-technical stakeholders Project We are looking for a Java Developer to join a team responsible for developing and maintaining core services related to advertising campaign management. The team builds solutions that enable business users and advertising agencies to create and manage advertising campaigns, which are then delivered to various advertising channels and platforms. The scope of responsibility also includes budgeting and billing services related to advertising activities. The team works closely with multiple engineering and product teams responsible for campaign delivery, frontend applications, and other business-critical domains. The environment consists of highly scalable backend systems, distributed services, and data-intensive solutions that support key business processes. Expected competences and knowledge Commercial experience in Java and/or Kotlin development Good understanding of backend application development using Spring Boot Knowledge of object-oriented programming principles and software design patterns Familiarity with microservices architecture and distributed systems concepts Experience working with relational databases PostgreSQL Basic knowledge of NoSQL databases MongoDB Understanding of asynchronous communication and event-driven systems Experience with REST APIs and integration between services Eagerness to learn and develop in a modern cloud-based environment Technologies you'll work with Java, Kotlin Spring Boot MongoDB PostgreSQL Kafka Event-Driven Architecture Google Cloud BigQuery Microservices REST APIs Git CI/CD Pipelines Cloud-based services and distributed systems Client – why choose this particular client from the Jit portfolio? Our Client dominates the Polish e-commerce arena as the market leader since 1999 . With a user base of over 20 million and growing, this well-established platform is at the forefront of e-commerce, constantly striving for growth through market expansion and investment. As a major player in technology, our Client boasts a talented IT team of over 1,000 employees who focus on developing their own cutting-edge technologies. Jit Team has had a successful partnership with our Client since spring 2021 , with multiple software development teams dedicated to our Client's platforms. These teams operate autonomously, designing platform components through micro-services. Working with our Client offers a chance to contribute to a solution used by millions on a daily basis and to tackle the challenge of delivering software at a massive scale , where even a single second of delay can have a significant impact. This project provides a unique opportunity to work with state-of-the-art technologies and tools, making it a rare and valuable experience. About Jit Team The Human Factor of IT - it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts , to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams. Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.