What if, in your next adventure, you were surrounded by people who, like you, look for an unlimited playground to explore, share, and test, would you care to hear more? You've opened the right door! As an R&D team, making sure your ideas are heard and encouraged is what we strive to do!

What You'll Do:

Criteo is looking for a Lead Machine Learning Engineer to take ownership of the Reco Ranker team, at the heart of Criteo's engine.
In close partnership with the Reco Retrieval team, the Reco Ranker team builds and operates the algorithms that determine, for every display, which products to show and in what order. The team's mission is to maximize relevance and performance at massive scale-ranking hundreds of candidate products under 10ms latency, for billions of ad impressions daily.

As a Lead ML Engineer, you will:

• Own and deliver the team's roadmap, with a strong focus on shipping and scaling robust ranking models in production, while keeping an eye on innovation through targeted research efforts.
• Act as a technical leader and hands-on contributor, driving design, prioritization and development decisions while mentoring and empowering the team.
• Design, train, and deploy at scale deep learning models for real-time product ranking-generic enough to scale across thousands of clients, yet adaptive to their individual needs.
• Ensure production-readiness at scale: build efficient and reliable pipelines that meet demanding latency and throughput requirements.
• Navigate the need for compromises and make informed trade-offs between competing priorities, system constraints, and modeling strategies.
• Collaborate closely with stakeholders, product, and technical teams to shape priorities, ensure continuous alignment on goals, and streamline integration paths.

Who You Are:

• You have a strong background in machine learning, ideally with hands-on experience in deep learning applied to recommendation, ranking, or personalization problems.
• You are skilled in software engineering, including production-grade systems and distributed computation (e.g., Python, C++, Scala, Spark).
• You have experience leading technical teams, setting direction, and mentoring others, while maintaining a collaborative, hands-on mindset.
• You are comfortable navigating trade-offs between innovation, reliability, and scalability, and you bring structure and clarity to complex challenges.
• You are motivated by impact at scale, and excited to optimize algorithms that run millions of times per second and directly drive business value.
• You bring a positive, pragmatic, and solutions-oriented mindset, and thrive in fast-paced environments where focus and resilience are key.

If you're passionate about building cutting-edge recommender systems and leading high-performing teams in a fast-paced, data-driven environment, come help shape the future of commerce media at Criteo.

We acknowledge that many candidates may not meet every single role requirement listed above. If your experience looks a little different from our requirements but you believe that you can still bring value to the role, we'd love to see your application!

Who We Are:

Criteo is the global commerce media company that enables marketers and media owners to deliver richer consumer experiences and drive better commerce outcomes through its industry leading Commerce Media Platform.

At Criteo, our culture is as unique as it is diverse. From our offices around the world or from home, our incredible team of 3,600 Criteos collaborates to develop an open and inclusive environment. We seek to ensure that all of our workers are treated equally, and we do not tolerate discrimination based on race, gender identity, gender, sexual orientation, color, national origin, religion, age, disability, political opinion, pregnancy, migrant status, ethnicity, marital or family status, or other protected characteristics at all stages of the employment lifecycle including how we attract and recruit, through promotions, pay decisions, benefits, career progression and development. We aim to ensure employment decisions and actions are based solely on business-related considerations and not on protected characteristics. As outlined in our Code of Business Conduct and Ethics, we strictly forbid any kind of discrimination, harassment, mistreatment or bullying towards colleagues, clients, suppliers, stakeholders, shareholders, or any visitors of Criteo. All of this supports us in our mission to power the world's marketers with trusted and impactful advertising encouraging discovery, innovation and choice in an open internet.

Why Join Us:

At Criteo, we take pride in being a caring culture and are committed to providing our employees with valuable benefits that support their physical, emotional and financial wellbeing, their interests and the important life events. We aim to create a place where people can grow and learn from each other while having a meaningful impact. We want to set you up for success in your job, and an important part of that includes comprehensive perks & benefits. Benefits may vary depending on the country where you work and the nature of your employment with Criteo. When determining compensation, we carefully consider a wide range of job-related factors, including experience, knowledge, skills, education, and location. These factors can cause your compensation to vary.