Senior Applied Scientist, Supply

Prolific; Greater London; Remote; GBP 90,000 - 150,000; Full time

Job summary

Prolific seeks a Senior Applied Scientist to lead optimization and recommender-system initiatives on the Supply Data Science team. You will shape problems, design scalable solutions, and collaborate with product and engineering to deploy models that improve participant matching and marketplace quality.

The role blends data science, ML, and statistics to turn promising approaches into production-ready solutions.

Qualifications

• Strong background in mathematical optimization and recommender systems.
• 5+ years applying ML, AI research, optimization, or recommender systems to production-scale problems.
• Ability to turn loosely defined problems into clear hypotheses, experiments, and metrics.
• Experience collaborating with product and engineering teams.
• Comfort working on ambiguous problems and taking initiative.

Skills

Optimization & recommender systems

Production ML

Hypothesis-driven experimentation

Experimentation & metrics

Marketplace dynamics

Education

MSc or PhD in CS/Math/Stats/ Economics or related

Tools

Python

Job description

Senior Applied Scientist

Prolific

You're join Prolific's Supply team, which is responsible for the health and growth of our participant marketplace, the supply side of our two-sided marketplace connecting participants and researchers. This is a senior role on an established Supply Data Science team, focused on marketplace dynamics—in particular driving participant supply, demand, and quality through advanced optimization techniques and recommendation algorithm expertise. You will work closely with existing specialists in this space to design, validate, and scale high-impact algorithmic systems that optimize study matching and participant experience. As a senior scientist, you will lead complex technical directions and help define the right problems to solve, driving both strategy and implementation.

The role

The Applied Scientist role is new to Prolific. It combines data science, ML, and statistics to build practical systems that drive real business outcomes. This isn't a pure research role, although you may explore papers and explore new ideas. The focus is on turning promising approaches into production-ready solutions. It is also not an ML engineering role: you don't need engineering experience, but you should understand what deploying a model involves and the practical constraints around it. We care about approaches that actually work in production, not ones that are too slow or expensive to run, and about the judgement to tell the difference.

What you'll bring

• Deep expertise in mathematical optimization and recommendation algorithms applied to large-scale matching or marketplace problems.
• Judgement about when to reach for simple statistics, classical ML, LLMs, or agentic approaches.
• 5+ years applying ML, AI research, optimization, or recommendation systems to complex production problems.
• Python skills sufficient to build, test, and iterate on working prototypes independently.
• Able to take a loosely defined product or customer problem and turn it into clear hypotheses, experiments, and metrics.
• You must be comfortable working on ambiguous problems and suggesting solutions rather than waiting to be told exactly what to do.

Nice to have

• An MSc or PhD in Computer Science, Maths, Statistics, Economics, Psychology, ML, or a related field—or equivalent knowledge gained another way.
• Experience working alongside product and engineering teams.

How you'll work

• You'll join an established Supply, Data Science team, working alongside existing specialists (for example, in marketplace economics).
• You don't need to have all the answers on day one, but you should be ready to get stuck in quickly.
• You spot problems worth solving and start on them, rather than waiting to be assigned.
• You will be comfortable (and ideally enjoy) collaborating with others.

Why Prolific is a great place to work

We've built a unique platform that connects researchers and companies with a global pool of participants, enabling the collection of high-quality, ethically sourced human behavioral data and feedback. This data is the cornerstone of developing more accurate, nuanced, and aligned AI systems.

We believe that the next leap in AI capabilities won't come solely from scaling existing models but from integrating diverse human perspectives and behaviors into AI development. By providing this crucial human data infrastructure, Prolific is positioning itself at the forefront of the next wave of AI innovation—one that reflects the breadth and the best of humanity.

Working for us will place you at the forefront of AI innovation, providing access to our unique human data platform and opportunities for groundbreaking research. Join us to enjoy a competitive salary, benefits, and remote working within our impactful, mission-driven culture.

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