Recommender Systems Lead

Rapidata; Zürich; Hybrid; CHF 190,000 - 240,000; Full time

Benefits offered by this job

Competitive salary

Equity

Growth opportunities

Startup culture

Mountain views office Zürich Center

Hardware budget

Unlimited snacks and drinks

Job summary

Rapidata in Zürich is hiring a Recommender Systems Lead to design, build and deploy high‑engagement ranking and personalization systems at global scale.

You will own success metrics, run offline evaluations and online experiments, and translate research ideas into production systems that move business metrics.

Ideal candidates have led production systems with strict latency (<5 ms), possess a strong statistical foundation, and can lead a small team in a fast‑growing startup.

Qualifications

• Proven experience building production-grade ranking, personalization, or decision systems.
• Experience validated in real-world systems.
• Latency-focused deployment experience (production).
• Strong ownership and ability to operate core systems.

Responsibilities

• Developing, Testing and Deploying recommender systems
• Defining and owning success metrics for short and long term
• Designing offline evaluation pipelines and online experimentation frameworks
• Translating research ideas into production-ready systems and measurable business impact
• Hiring and leading a small team

Skills

Ranking systems

Low latency

Statistics/mathematics

Ownership/autonomy

English communication

Job description

About Rapidata

Rapidata provides an API to humans that is revolutionizing the data generation and annotation industry. It delivers highly scalable and extremely fast human data that fuels the AI systems of the future. We have a diverse user base of over 10 million active users from all over the world. Naturally, this means different people are good at different things. To optimize both efficiency and quality of responses, we need to assign the right tasks to the right person in real time, at global scale.

The Role

We're looking to hire a Recommender Systems Lead, a senior professional with significant experience in the topic, coming from either a production-heavy industry background or a strong applied research background. Ideally, you've built high-engagement recommendation systems — maybe you made people scroll TikToks a little longer or spend way too much on impulse purchases. Now it's time to transfer that knowledge to improve data labeling for the next generation of AI models.

You should have built a system like this in the past, saw what does and does not work, and also know the pitfalls of actually running a system that makes millions of decisions per hour under strict latency constraints (<5ms). You'll have the opportunity to introduce new modeling approaches, rigorously evaluate them, and see them deployed in a live system operating at global scale — closing the loop between theory, experimentation, and production.

Responsibilities

• Developing, Testing and Deploying recommender systems

• Defining and owning success metrics (both for short-term and long-term horizons)

• Designing offline evaluation pipelines and online experimentation frameworks — our platform is perfect for continuous A/B tests

• Showing clear performance improvements

• Translating research ideas into production-ready systems and measurable business impact

• Hiring and leading a small team

Requirements

• Proven experience building and operating production-grade ranking, personalization, or decision systems and/or leading applied research that was validated in real-world systems

• Experience in deploying systems with strict latency constraints

• Solid statistical and mathematical foundation

• High ownership and autonomy over a core company system

• Excellent English communication skills, both oral and written

Nice-to-Have

• Ability to work in the Bay Area or Zürich

• Publications or patents in relevant areas (e.g. recommender systems, ranking, bandits, applied ML), especially where ideas were validated on real-world data or systems

What We Offer

• Competitive salary and equity in a startup with strong growth, IP and backed by top-tier VCs

• Opportunity to join a fast growing startup early, giving you an outsized opportunity to shape where the company goes

• Opportunities for personal and professional growth as our team expands

• Fun and open (startup) culture

• Spacious mountain views office located in Zürich Center near Sihlcity (3 min from Binz Train station). Large Terrace with Tabletennis, Pizza Oven, Hammock and a BBQ

• Hardware budget tailored to your preferences

• Unlimited snacks and drinks of your choice