Lead Applied Scientist, Prolific
12 Month Fixed Term Contract
High-quality human-powered data at scale
Posted today
High-quality human-powered data at scale
101-200 employees
Posted today
101-200 employees
Company mission
To accelerate human understanding.
Role
Who you are
- Ideal for someone with deep scientific judgement, strong applied ML skills, and a practical bias toward methods that work in real customer and product contexts
- PhD or MSc in Computer Science, Mathematics, Statistics, Machine Learning, or a related field
- 3+ years of applied ML, AI research, or data science experience with demonstrated real-world impact
- Experience with human-in-the-loop AI systems, including RLHF, annotation pipelines, data quality modelling, judgement aggregation, benchmarks, or AI evaluation
- Fluency with modern LLM and agentic techniques, such as Retrieval-Augmented Generation (RAG), LLM-as-judge, multi-agent workflows, synthetic data generation, and automated quality review
- Strong Python skills and the ability to quickly build, test, and iterate on working prototypes
- Good judgement on when to use simple statistical methods, classical ML, LLMs, or agentic approaches
- Ability to translate ambiguous product or customer problems into clear hypotheses, experiments, metrics, and reusable methodologies
- Strong cross-functional communication and experience partnering with product and engineering teams
What the job involves
- As an Applied Scientist, you will design and prototype AI/ML methods that improve data quality, scale human judgement, and support robust AI evaluation workflows
- You will work on applied problems such as quality modelling, judgement aggregation, evaluation design, LLM-assisted review, and reliability testing for AI systems
- This is not a pure research role or a production ML engineering role. You will turn ambiguous problems into clear methodologies, benchmarks, models, and prototypes that product and engineering teams can adopt
- Prototype AI/ML methods to improve human data quality, judgement aggregation, and AI evaluation workflows
- Design experiments, benchmarks, and reliability tests to measure whether new methods improve quality, efficiency, or customer outcomes
- Apply classical ML, statistics, LLMs, and agentic techniques where they create practical value
- Use modern AI tools to accelerate prototyping, experimentation, and iteration
- Partner closely with product and engineering to translate scientific methods into scalable platform capabilities
- Communicate technical assumptions, trade-offs, and recommendations clearly across technical and non-technical teams
Salary benchmarks
Our take
Founded in 2014, Prolific is a marketplace and data analysis company that provides researchers with a network of test participants. From eye-tracking to human-facing AI applications, Prolific’s network acts as both a recruiter for test participants and as a marketplace for researchers scientists to hire said participants.
Founded in 2014, it’s already used by the likes of Google, Stanford, Oxford and Kings College London Universities to test new AI products, providing “stress tests” for its clients. Prolific’s user base now counts over 2000 potential test subjects, whilst researchers leverage its network to launch surveys, tests and evaluation tasks every 2 minutes.
An indicator of Prolific’s success is maintaining of profitability for years after its initial Y Combinator investment. In 2024, it raised $32 million in Series A to maintain its healthy position. This funding will allow it to expand its operations.
Freddie
Company Specialist at Welcome to the Jungle
Insights
Company
Funding (1 round)
Jul 2023
$33.5m
Series A
Total funding: $33.5m
Company benefits
- Bank holiday swaps
- Enhanced sick pay
- L&D budget – £1000 per year
- 25 days annual leave + bank holidays
Company values
- We win together
- We care deeply about our customers
- We make every minute count
- We're optimistic and find a way
- We embrace change
- We aim high
Company HQ
Kings Cross, London, UK
Leadership
Phelim Bradley
(Co-Founder & CEO)Currently also Venture Partner at Pioneer Fund. Previously Dphil at Wellcome Trust Centre for Human Genetics, Bioinformatics Intern at Illumina and MPhil of Computer Biology at University of Cambridge.
Diversity, Equity & Inclusion at Prolific
- At Prolific, we want all of our employees, researchers, and participants to be included and so we commit to having ongoing discussions about diversity and inclusion and regularly look at areas where we can improve. This policy aims to: - treat all our employees fairly and respectfully, regardless of their job status, location, or work hours ⏰ - avoid any illegal discrimination based on age, disability, gender, gender identity, marriage or civil partnership, pregnancy and maternity, race or ethnicity, religion or belief, sexual orientation, and traveler status. These are protected by the UK Equality Act (2010), Ireland Employment Equality Act (2004), Americans with Disabilities Act (ADA) at the federal level and the New York State Human Rights Law (NYSHRL) at the state level. ⚖️ - refuse to tolerate any kind of illegal discrimination 🙅🏻♀️. This includes pay and benefits, work conditions, grievance and discipline handling, termination, redundancy, parental leave, flexible working requests, employment selection, promotion, training, and other opportunities for development.
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