April 24, 2026

Senior Staff ll, Machine Learning Engineer (Tech Lead)

Senior • On-site

187,000 - 322,000 USD/yr

Mountain View, CA

Sr. Staff ll, Machine Learning Engineer - Search

We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did we ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we’re collectively disrupting the multi-billion-dollar e-commerce industry from the ground up. We are one of the fastest-growing e-commerce companies that established an unparalleled reputation for being a dominant and reliable force in South Korean commerce.

We are proud to have the best of both worlds — a startup culture with the resources of a large global public company. This fuels us to continue our growth and launch new services at the speed we have been since our inception. We are all entrepreneurial surrounded by opportunities to drive new initiatives and innovations. At our core, we are bold and ambitious people that like to get our hands dirty and make a hands-on impact. At Coupang, you will see yourself, your colleagues, your team, and the company grow every day.

Our mission to build the future of commerce is real. We push the boundaries of what’s possible to solve problems and break traditional tradeoffs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world.

About the Role

As a Senior Staff Machine Learning Engineer in Search and Discovery, you will leverage the most advanced algorithms to improve Coupang’s product search and discovery quality. You are expected to be a leading expert in one or multiple areas including information retrieval, recommendation systems, machine learning, deep learning or natural language processing. The ideal candidates are pragmatic, resourceful, and embrace challenges that are seemingly impossible. The ideal candidates also have rich industry experience and a track record of delivering highly impactful projects.

What You Will Do

  • Root causes the bottle neck of the current search and recommendation systems and quantifies the defects.
  • Propose solutions which address the search and discovery defects and leverage the state-of-the-art technologies, including ML, DL and large language model.
  • Implement the solutions and conduct AB tests.
  • Be a thought leader and able to gain consensus in the organization when needed.

Some example projects include:

  • Personalization ranking model and its integration to Search ranking stack.
  • Personalized retrieval
  • Recommendation model for all Discovery interfaces.
  • User understanding and modeling

What We’re Looking For

Required Qualifications

  • 10+ years of experience in related fields including Search, Information Retrieval, RecSys, ML, DL or NLP.
  • Proficient coding skills in Java, C++ or Python
  • Problem solver, Pragmatic and Open-minded
  • Master Degree in Computer Science or related fields.
  • Experience with handling large data volumes in a distributed environment

Preferred Qualifications

  • Love to explore new territory of technology andgo deep ondomainknowledge.
  • Ability to think outside-the-box and challenge conventional wisdom.
  • A passion to explore, improve, automate and optimize distributed systems and tools.
  • PhD in Computer Science or related Engineering majors
  • Bonus points for experience at ecommerce or social network or search companies

Pay & Benefits:

Our compensation reflects the cost of labor across several US geographic markets. At Coupang, your base pay is one part of your total compensation.

The base pay for this position ranges from $187,000/year in our lowest geographic market to $322,000/year in our highest geographic market. Pay is based on several factors including market location and may vary depending onjob-related knowledge, skills, and experience.

General Description of All Benefits:

  • Medical/Dental/Vision/Life, AD&D insurance
  • Flexible Spending Accounts (FSA) & Health Savings Account (HSA)
  • Long-term/Short-term Disability
  • Employee Assistance Program (EAP) program
  • 401K Plan with Company Match
  • 18-21 days of the Paid Time Off (PTO) a year based on the tenure
  • 12 Public Holidays
  • Paid Parental leave
  • Pre-tax commuterbenefits
  • MTV - [Free] Electric Car Charging Station

General Description of Other Compensation:

“Other Compensation” includes, but is not limited to, bonuses, equity, or other forms of compensation that would be offered to the hired applicant in addition to their established salary range or wage scale.

Equal Opportunities for All

Coupang is an equal opportunity employer. Our unprecedented success could not be possible without the valuable inputs of our globally diverse team.

Coupang is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to actual or perceived race (including traits historically associated with race, including but not limited to hair texture and protective hair styles), color, religion, religious creed (including religious dress and grooming practices), sex or gender (including pregnancy, childbirth, breastfeeding, and medical conditions related to pregnancy, childbirth or breastfeeding), gender identity, gender expression, sexual orientation, ,ancestry, national origin (including language use restrictions), age (40 and over), physical or mental disability, medical condition, genetic information, HIV/AIDS or Hepatitis C status, family status (including but not limited to marital or domestic partnership status), military or veteran status, use of a trained dog guide or service animal, political activities or affiliations, ancestry, citizenship, family and medical leave status, status as a victim of any violent crime, or any other characteristic or class protected by the laws or regulations in the locations where we operate.Coupang is also committed to providing a safe work environment for its employees and its consumers. If you need assistance and/or reasonable accommodation in the application of recruiting process due to a disability, please contact us atusrecruiting@coupang.com.



Similar jobs you might like

Technology

Coupang

Senior Staff Machine Learning Infrastructure Engineer – Search & Discovery

Senior

On-site

Mountain View, CA

174,000 - 299,000 USD/yr

🏢 Summary: Senior Staff Software Engineer (ML Infra) role focused on building scalable offline and online machine learning platforms for search, ranking, and recommendation systems. The position involves designing and optimizing big data pipelines and real-time ML inference services that process billions of user interactions and petabytes of logs. The engineer will drive end-to-end ML infrastructure to support large-scale model training and high-throughput, low-latency serving. 🗂️ Requirements: Bachelor’s degree in Computer Science, Electrical Engineering, Mathematics, Statistics or related field, 8+ years of professional experience in applied machine learning, Strong experience in machine learning, deep learning, and statistical modeling, Proficiency in Python and/or Java, Experience building production-grade ML systems, Solid knowledge of data structures and algorithms, Experience with big data processing and ETL frameworks, Experience deploying scalable data pipelines processing large-scale data, Experience building high-throughput, low-latency services, Experience with cloud platforms 📃 Skills: Python, Java, Hadoop, Hive, Presto, Spark, Scala, Airflow, TensorFlow, PyTorch, AWS, GCP, ETL, ML, DeepLearning, SQL 🏢 Description: We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did I ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we’re collectively disrupting the multi-billion-dollar e-commerce industry from the ground up. We are one of the fastest-growing e-commerce companies that established an unparalleled reputation for being a dominant and reliable force in South Korean commerce. We are proud to have the best of both worlds — a startup culture with the resources of a large global public company. This fuels us to continue our growth and launch new services at the speed we have been since our inception. We are all entrepreneurs surrounded by opportunities to drive new initiatives and innovations. At our core, we are bold and ambitious people that like to get our hands dirty and make a hands-on impact. At Coupang, you will see yourself, your colleagues, your team, and the company grow every day. Our mission to build the future of commerce is real. We push the boundaries of what’s possible to solve problems and break traditional tradeoffs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world. Role Overview As our Senior Staff Software Engineer, ML infra Engineer for Search & Discovery organization, you will be in charge of designing and implementing durable & efficient software solutions that handle massive volume of structured and unstructured data needed to train complex ML models and efficiently serve them online. The Search & Discovery organization is responsible for optimizing customers' navigation experience and driving long-term growth. Every week millions of customers use search in our app or on coupang.com, more than one third of them make purchases. Over half of the Coupang sales are directly attributed to search and recommendation. Many business initiatives and growth strategies are driven or boosted by ranking and recommendation. This role is an opportunity to build scalable offline and online ML platforms to support ranking and recommendation, and business decision making. You will be handling billions of records of user interaction data, and petabytes of raw log files, and transforming them into data objects that can be easily consumed by engineers and scientists. You will also be responsible for serving complex ML models in real time to help millions of Coupang customers search and discover products. If you are passionate about big data engineering and scalable serving systems, you want to make real business impact, and you are a true problem solver, this is the right job for you. What You Will Do Proactively drive the execution of end-to-end data platform, data quality roadmap for Search & Discovery ML efforts Take ownership, consolidate and optimize the Search & Discovery core data logging, processing, and ML model training pipelines Develop and scale data infrastructure that powers batch and real-time data processing, monitoring, and debugging for ML experiments Drive design and implementation of scalable ML based ranking system and online ML inference services Build strong cross-functional partnerships with Data Scientists, Analysts, Product Managers, Indexing Platform Engineers, Ranking Engineers and Data Platform Engineers to understand both the offline and online needs and deliver on those needs Research, analyze and select technical approaches for solving difficult and challenging development and integration problems, coach and mentor other engineers in process and methodologies Basic Qualifications Bachelor's degree in computer science, electrical engineering, mathematics, statistics or closely related fields 8 years of professional experience in applied machine learning Experience in machine learning, deep learning, and statistical modeling Proficiency in Python and/or Java, with experience in building production grade ML systems Preferred Qualifications Computer science fundamentals: data structures, algorithms, performance complexity, and implications of computer architecture on software performance (e.g., I/O and memory tuning) Experience with Big Data tools and ETL frameworks (Hadoop, Hive, Presto, Spark, Scala, Apache Airflow, etc.) Experience with ML frameworks such as Tensorflow and Pytorch Experience with deploying highly robust and scalable data pipelines processing petabytes of data Experience in managing mission critical services with high throughput and low latency Experience with integrating applications and platforms with cloud technologies (i.e, AWS and GCP) Strong verbal and written communication skills Ability to conduct meetings and make professional presentations, and explain complex concepts and technical material to non-technical users Experience with machine learning platform for search & discovery related rankings is a strong plus Pay & Benefits Our compensation reflects the cost of living across several US geographic markets. At Coupang, your base pay is one part of your total compensation. The base pay for this position ranges from $174,000K/year to $299,000K/year. Pay is based on several factors including market location and may vary depending on job-related knowledge, skills, and experience. General Description of All Benefits Medical/Dental/Vision/Life, AD&D insurance Flexible Spending Accounts (FSA) & Health Savings Account (HSA) Long-term/Short-term Disability Employee Assistance Program (EAP) program 401K Plan with Company Match 18-21 days of the Paid Time Off (PTO) a year based on the tenure 12 Public Holidays Paid Parental leave Pre-tax commuter benefits MTV - [Free] Electric Car Charging Station General Description of Other Compensation "Other Compensation" includes, but is not limited to, bonuses, equity, or other forms of compensation that wouldbe offered to the hired applicant in addition to their established salary range orwage scale. Recruitment Process and Others Recruitment Process Application Review - Phone Interview - Onsite (or Virtual Onsite) Interview – Offer The exact nature of the recruitment process may vary according to the specific job and may be changed due to scheduling or other circumstances. Interview schedules and the results will be informed to the applicant via the e-mail address submitted at the application stage Details to Consider This job posting may be closed prior to the stated end date for application if all openings are filled. Coupang has the right to rescind an offer of employment if a candidate is found to have submitted false information as part of the application process. Those eligible for employment protection (recipients of veteran’s benefits, the disabled, etc.) may receive preferential treatment for employment in accordance with applicable laws. Privacy Notice Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located below:https://www.coupang.jobs/privacy-policy/ Coupang is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to actual or perceived race (including traits historically associated with race, including but not limited to hair texture and protective hair styles), color, religion, religious creed (including religious dress and grooming practices), sex or gender (including pregnancy, childbirth, breastfeeding, and medical conditions related to pregnancy, childbirth or breastfeeding), gender identity, gender expression, sexual orientation, ,ancestry, national origin (including language use restrictions), age (40 and over), physical or mental disability, medical condition, genetic information, HIV/AIDS or Hepatitis C status, family status (including but not limited to marital or domestic partnership status), military or veteran status, use of a trained dog guide or service animal, political activities or affiliations, ancestry, citizenship, family and medical leave status, status as a victim of any violent crime, or any other characteristic or class protected by the laws or regulations in the locations where we operate. Coupang is also committed to providing a safe work environment for its employees and its consumers. If you need assistance and/or a reasonable accommodation in the application of recruiting process due to a disability, please contact us at usrecruiting@coupang.com. Job Requisition ID: R0069890

Technology

Coupang

Sr. Staff Software Engineer, Security

Senior

On-site

Mountain View, CA , +1

1,450 - 24,917 USD/yr

🏢 Summary: Senior Staff Software Engineer role focused on leading the design and development of secure, scalable backend systems, with strong emphasis on security architecture and distributed systems. The position combines hands-on Java development with AWS cloud services, driving authentication, authorization, API security, and secure AI integration at enterprise scale. You will provide technical leadership to ensure reliability, performance, and secure SDLC practices across mission-critical platforms. 🗂️ Requirements: Bachelor’s degree in Computer Science or related field, 8+ years of professional software development and security engineering experience, 7+ years of Java programming experience, Experience designing large-scale distributed systems, Strong knowledge of security architecture, Experience building secure, scalable backend systems, Experience with AWS cloud services, Experience implementing authentication and authorization mechanisms, Experience with cryptography and PKI systems 📃 Skills: Java, Spring, AWS, EKS, S3, Lambda, RDS, IAM, KMS, Microservices, REST, OAuth, OIDC, RBAC, ABAC, SCIM, SSO, Cryptography, PKI, Kubernetes, AI, LLM, RAG, Embeddings 🏢 Description: We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did we ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we’re collectively disrupting the multi-billion-dollar e-commerce industry from the ground up. We are one of the fastest-growing e-commerce companies that established an unparalleled reputation for being a dominant and reliable force in South Korean commerce. We are proud to have the best of both worlds — a startup culture with the resources of a large global public company. This fuels us to continue our growth and launch new services at the speed we have been since our inception. We are all entrepreneurs surrounded by opportunities to drive new initiatives and innovations. At our core, we are bold and ambitious people that like to get our hands dirty and make a hands-on impact. At Coupang, you will see yourself, your colleagues, your team, and the company grow every day. Our mission to build the future of commerce is real. We push the boundaries of what’s possible to solve problems and break traditional tradeoffs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world. Role Overview We are seeking a highly skilled Senior Staff Software Engineer with deep technical expertise in Security and a passion for building secure, reliable, and scalable systems. This role focuses on technical leadership, architecture, and hands-on development to ensure the security and resilience of our core platforms. You will drive the security, quality, and reliability of backend systems while influencing architecture decisions, mentoring engineers, and partnering with product teams on strategic initiatives. What You Will Do Architect and implement secure, scalable backend systems using Java (Spring Boot) and AWS cloud-native services. Lead technical design reviews, enforce security best practices, and ensure system reliability and performance. Develop and integrate security features such as authentication, authorization, and identity management (SSO, OIDC, RBAC/ABAC, SCIM). Design and implement API security patterns and API authorization at scale for microservices and service mesh environments. Embed Generative AI capabilities (e.g., embeddings, RAG, LLM APIs) into product workflows securely and responsibly. Write and review code, unblock complex technical challenges, and make critical architectural decisions. Champion secure SDLC practices, cryptography standards, and compliance requirements. Collaborate with cross-functional teams to define technical roadmaps and deliver mission-critical systems at scale. Minimum Qualifications Bachelor’s degree in Computer Science or related technical field. 8 years of professional software development and security engineering experience. Proven experience designing and developing large-scale distributed systems. Strong knowledge of security architecture Preferred Qualifications Recent hands-on experience (last 3–4 years) building secure, distributed systems at scale, with strong exposure to AI/ML development and hosting in production environments. Experience with cloud platforms (AWS, Azure, GCP) for identity, ML infrastructure, and secure deployment. Familiarity with Generative AI integration and responsible implementation of LLM-based workflows. Exposure to data security principles, including encryption, secure data pipelines, and compliance frameworks. Ability to influence technical direction and mentor engineers in security best practices. Proven track record of delivering mission-critical, scalable systems in production at enterprise scale. Expertise in Java, Spring Boot, and AWS architecture/services (EKS, S3, Lambda, RDS, IAM, KMS). 7+ years of solid experience with fundamental algorithms, system design, and large distributed systems. Deep experience in cryptography and PKI systems, including certificate management and secure key lifecycle 7+ years of coding experience, specifically in Java. Strong knowledge of security architecture, authentication/authorization, and cryptographic principles. Hands-on experience in building large-scale serving and data infrastructure. Experience with service-oriented architecture and web application/services development Practical experience in utilizing AWS (Amazon Web Services). Experience in designing and constructing machine learning-based applications and systems. Experience in leading cross-team system design and execution. Pay & Benefits Our compensation reflects the cost of living across several US geographic markets. At Coupang, your base pay is one part of your total compensation. The base pay for this position ranges from $174,00/year to $299,000/year. Pay is based on several factors including market location and may vary depending on job-related knowledge, skills, and experience. General Description of All Benefits Medical/Dental/Vision/Life, AD&D insurance Flexible Spending Accounts (FSA) & Health Savings Account (HSA) Long-term/Short-term Disability Employee Assistance Program (EAP) program 401K Plan with Company Match 18-21 days of the Paid Time Off (PTO) a year based on the tenure 12 Public Holidays Paid Parental leave Pre-tax commuter benefits MTV - [Free] Electric Car Charging Station General Description of Other Compensation “Other Compensation” includes, but is not limited to, bonuses, equity, or other forms of compensation that wouldbe offered to the hired applicant in addition to their established salary range orwage scale. Recruitment Process Application Review - Phone Interview - Onsite (or Virtual Onsite) Interview – Offer The exact nature of the recruitment process may vary according to the specific job and may be changed due to scheduling or other circumstances. Interview schedules and the results will be informed to the applicant via the e-mail address submitted at the application stage. Details to Consider This job posting may be closed prior to the stated end date for application if all openings are filled. Coupang has the right to rescind an offer of employment if a candidate is found to have submitted false information as part of the application process. Those eligible for employment protection (recipients of veteran’s benefits, the disabled, etc.) may receive preferential treatment for employment in accordance with applicable laws. Privacy Notice Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located below:https://www.coupang.jobs/privacy-policy/ Coupang is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, or gender (including pregnancy, gender identity, gender expression, sexual orientation, transgender status), national origin, age, disability, medical condition, HIV/AIDS or Hepatitis C status, marital status, military or veteran status, use of a trained dog guide or service animal, political activities, or affiliations, citizenship, or any other characteristic or class protected by the laws or regulations in the locations where we operate. If you need assistance and/or reasonable accommodation in the recruiting process due to a disability, please contact us at usrecruiting@coupang.com. Job Requisition ID: R0067878

Technology

MOTIFE

Senior Machine Learning Engineer

Senior

Hybrid

Warsaw, Poland

31,000 - 35,000 PLN/mo

🏢 Summary: Senior Machine Learning Engineer role focused on building and scaling end-to-end recommendation systems for personalized content and workout experiences. The position involves developing real-time ML services, running experiments, and deploying production-grade models in a cloud-based environment. You will contribute to unified recommendation architecture and LLM-driven personalization initiatives. 🗂️ Requirements: 4+ years of experience in machine learning, Experience in recommender systems or applied ML domains, Degree in Computer Science, Machine Learning, Statistics, Mathematics or related quantitative field, Hands-on experience building, training and evaluating ML models, Strong software engineering skills, Professional experience with Python, Experience with large-scale data pipelines, Experience with distributed data processing, Experience with Spark and Airflow, Experience with AWS or similar cloud environment, Experience with Kubernetes and production serving technologies, Experience with A/B testing and experiment analysis 📃 Skills: Python, Spark, Airflow, AWS, S3, Kubernetes, RecommenderSystems, DeepLearning, Transformers, LLMs, MLOps, REST, gRPC, FastAPI, ABTesting 🏢 Description: We are hiring on behalf of our client, a global innovator in fitness and wellness technology. Their mission is to empower people to live fit, strong, long, and happy lives by delivering integrated experiences to millions of members anytime, anywhere. We are looking for a Senior Machine Learning Engineer to join the Personalization team, which owns the recommendation systems powering content discovery across the ecosystem. In this role, you will work on end-to-end ML systems: building and training models, improving real-time recommendation services, running experiments, and deploying scalable solutions into production. You will help evolve the recommendation platform from multiple models toward a more unified, real-time architecture, while also contributing to company's IQ initiatives involving LLMs, personalized plans, and AI-powered member experiences. Key takeaways: Stack : Python, Spark, Airflow, AWS, S3, Kubernetes, recommender systems, Deep Learning, Transformers, LLMs, MLOps, REST/gRPC/FastAPI, A/B testing Salary : 31 000 PLN - 35 000 PLN gross on the Contract of Employment Working model : Hybrid - 3 days/week from the office Location : ul. Grzybowska 60, Warsaw Recruitment process : A call with MOTIFE Recruiter Hiring Manager screening Coding interview Panel interviews with the team (coding, architecture, and cross-collaboration interviews, Hiring Manager meeting) Responsibilities: Build, train, evaluate, and improve ML models powering personalized workout and content recommendations. Develop and maintain data and ML pipelines using Python, Spark, Airflow, AWS, and S3. Productionize, deploy, monitor, and optimize ML models and recommendation services. Improve real-time model serving, including latency, scalability, reliability, and infrastructure costs. Support the evolution of recommendation systems toward unified rankers, candidate generation, and inference services. Run A/B tests and analyze experiment results with Product Analysts to measure product and member impact. Contribute to IQ initiatives, including personalized plans, insights, LLM-based features, and responsible AI practices. Collaborate with ML Engineers, Data Engineers, Software Engineers, Platform Engineers, Product Managers, and Analysts to deliver scalable personalization features. Requirements: 4+ years of experience in machine learning, ideally in recommender systems, NLP, computer vision, or another applied ML domain. Degree in Computer Science, Machine Learning, Statistics, Mathematics, Operational Research, or another quantitative field. Strong hands-on experience building, training, evaluating, and improving ML models. Solid software engineering skills, including clean code, data structures, algorithms, and production readiness. Professional experience with Python; experience with Java, Kotlin, Go, C, or C++ is a plus. Experience with large-scale data pipelines, distributed processing, and orchestration tools such as Spark and Airflow. Familiarity with cloud-based ML environments, preferably AWS, and production serving technologies such as Kubernetes, REST, gRPC, or FastAPI. Strong communication skills and the ability to work cross-functionally with product, analytics, platform, data, and engineering teams. What we offer: 100% paid medical care Multisport Creative tax (KUP) Home office allowance MacBook Pro Apply now If this sounds like your next step, we’d love to hear from you! Please apply via our careers page and submit your CV in English.

Technology

Allegro

Senior Research Engineer - Learning to Rank

Senior

Hybrid

Warsaw, Poland

🏢 Summary: Senior Research Engineer role focused on designing, evaluating, and deploying production-grade machine learning models for search, ranking, and ads at scale. The position combines applied ML research with end-to-end ownership of solutions, from data exploration to production deployment. It involves translating state-of-the-art research into business impact while mentoring others and collaborating on large-scale systems. 🗂️ Requirements: Master’s or PhD in Machine Learning, Computer Science, Mathematics, Statistics or related STEM field, Strong knowledge of deep learning techniques, Experience in at least one domain: Information Retrieval or Natural Language Processing, Ability to conduct scientific research and iterative experimentation, Experience working with complex, real-world datasets, Proficiency in Python for ML development, Experience with ML frameworks such as PyTorch or TensorFlow 📃 Skills: Python, PyTorch, TensorFlow, Transformers, Pandas, NumPy, DeepLearning, NeuralNetworks, ContrastiveLearning, SemiSupervisedLearning, InformationRetrieval, NLP, Kubernetes, Docker, GitHub, GitHubActions, GCP, AWS, Azure, LLMs 🏢 Description: In the Learning to Rank team we develop machine learning models for search, ranking and ads. Our models serve millions of searches a day. We develop and apply state-of-the-art machine learning methods, helping Allegro grow and innovate with artificial intelligence. Beyond bringing AI to production, we are committed to advance the understanding of machine learning through open collaboration with the scientific community. About the role: As a Senior Research Engineer, you will work at the intersection of cutting-edge machine learning research and real-world products used at scale. You’ll take ownership of ML solutions end to end - from exploring complex data and selecting the right methods, to rigorous evaluation and production deployment. This role is for someone who enjoys navigating uncertainty, keeping pace with a fast-moving ML landscape, and turning research insights into tangible business impact, while also shaping ML expertise within the team and beyond. In your daily work you will handle the following tasks End-to-end ML ownership: Design and deliver production-ready machine learning solutions for Allegro products Data exploration: Analyze and understand complex data sets, identifying relevant data sources for ML use cases Model development & evaluation: Train, evaluate, and experiment with applied ML models using reliable evaluation methods Applied ML research: Translate state-of-the-art ML research into practical improvements for real-world solutions Tooling & methodology: Select ML tools and techniques that best fit concrete business needs Production collaboration: Work closely with cross-functional teams to deploy ML solutions into production Knowledge sharing: Spread ML expertise through internal sessions, presentations, and research activities Mentorship & expertise: Support junior team members and act as a trusted ML expert within the organization We are looking for people who Have a master's or PhD in machine learning, mathematics, computer science, statistics or other STEM fields Have a good knowledge of deep learning techniques (neural networks, contrastive learning, semi-supervised learning) in at least one domain (information retrieval, natural language generation or understanding, etc.) Know the methodology of conducting scientific research and the use of iterative processes of conducting experiments Have experience in working with real data that deviate from the standard, well-developed collections used in research Know Python and libraries necessary to work with model development (PyTorch, Tensorflow, Transformers, Pandas, Numpy, etc.) Nice-to-have: Understanding of Information Retrieval (IR) area Published research papers in ML-related topics Experience in business cooperation, deployments of ML-based solutions in commercial environments Prior experience in running large-scale computation on cloud platform (GCP, AWS or Azure) Prior experience in using LLMs for synthetic data generation/solving business problems 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. Long term discretionary incentive plan based on Allegro.eu shares (restricted stock units). 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!

Technology

Allegro

Senior Research Engineer - Learning to Rank

Senior

Hybrid

Warsaw, Poland

🏢 Summary: Senior Research Engineer role focused on designing, developing, and deploying production-ready machine learning models for search, ranking, and ads at scale. The position involves end-to-end ML ownership, from data exploration and experimentation to evaluation and production deployment, while translating state-of-the-art research into business impact. The role combines applied ML research with large-scale production collaboration. 🗂️ Requirements: Master’s or PhD in Machine Learning, Mathematics, Computer Science, Statistics, or related STEM field, Strong knowledge of deep learning techniques, Experience in at least one domain: Information Retrieval or Natural Language Processing, Ability to design and conduct scientific experiments using iterative methodologies, Experience working with complex, real-world datasets, Proficiency in Python, Experience with ML model development libraries (PyTorch or TensorFlow) 📃 Skills: Python, PyTorch, TensorFlow, Transformers, Pandas, NumPy, DeepLearning, NeuralNetworks, ContrastiveLearning, SemiSupervisedLearning, InformationRetrieval, NLP, LLMs, GCP, AWS, Azure, Kubernetes, Docker, Consul, GitHub, GitHubActions 🏢 Description: In the Learning to Rank team we develop machine learning models for search, ranking and ads. Our models serve millions of searches a day. We develop and apply state-of-the-art machine learning methods, helping Allegro grow and innovate with artificial intelligence. Beyond bringing AI to production, we are committed to advance the understanding of machine learning through open collaboration with the scientific community. About the role: As a Senior Research Engineer, you will work at the intersection of cutting-edge machine learning research and real-world products used at scale. You’ll take ownership of ML solutions end to end - from exploring complex data and selecting the right methods, to rigorous evaluation and production deployment. This role is for someone who enjoys navigating uncertainty, keeping pace with a fast-moving ML landscape, and turning research insights into tangible business impact, while also shaping ML expertise within the team and beyond. In your daily work you will handle the following tasks End-to-end ML ownership: Design and deliver production-ready machine learning solutions for Allegro products Data exploration: Analyze and understand complex data sets, identifying relevant data sources for ML use cases Model development & evaluation: Train, evaluate, and experiment with applied ML models using reliable evaluation methods Applied ML research: Translate state-of-the-art ML research into practical improvements for real-world solutions Tooling & methodology: Select ML tools and techniques that best fit concrete business needs Production collaboration: Work closely with cross-functional teams to deploy ML solutions into production Knowledge sharing: Spread ML expertise through internal sessions, presentations, and research activities Mentorship & expertise: Support junior team members and act as a trusted ML expert within the organization We are looking for people who Have a master's or PhD in machine learning, mathematics, computer science, statistics or other STEM fields Have a good knowledge of deep learning techniques (neural networks, contrastive learning, semi-supervised learning) in at least one domain (information retrieval, natural language generation or understanding, etc.) Know the methodology of conducting scientific research and the use of iterative processes of conducting experiments Have experience in working with real data that deviate from the standard, well-developed collections used in research Know Python and libraries necessary to work with model development (PyTorch, Tensorflow, Transformers, Pandas, Numpy, etc.) Nice-to-have: Understanding of Information Retrieval (IR) area Published research papers in ML-related topics Experience in business cooperation, deployments of ML-based solutions in commercial environments Prior experience in running large-scale computation on cloud platform (GCP, AWS or Azure) Prior experience in using LLMs for synthetic data generation/solving business problems 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. Long term discretionary incentive plan based on Allegro.eu shares (restricted stock units). 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!