--- title: 'Senior Software Engineer (Agent Training and Evals) at Prolific' canonical: 'https://feeny.ai/job/senior-software-engineer-agent-training-and-evals-prolific-united-kingdom-5faxrv5p4b9z' type: 'job' last_seen: '2026-10-18' --- # Senior Software Engineer (Agent Training and Evals) at Prolific - **Company:** Prolific - **Location:** United Kingdom - **Work type:** remote - **Posted:** 2026-09-11 - **Last confirmed live:** 2026-10-18 - **Apply:** https://job-boards.eu.greenhouse.io/prolific/jobs/4952068101 ## Job description Senior Software Engineer - (Agent Training and Evals) Engineering Prolific Prolific is not just another player in the AI space – we are the architects of the human data infrastructure that's reshaping the landscape of AI development. In a world where foundational AI technologies are increasingly commoditized, it's the quality and diversity of human-generated data that truly differentiates products and models. ## The role - As a Senior Software Engineer, you'll be one of the first engineers on our Agent Training & Evals team. - You'll build infrastructure to evaluate AI agents at scale against real human expertise, in safe and secure environments. The better we get at this, the more useful, reliable and safe agents become. - This is a genuine 0→1 role. There isn't a well-established playbook or existing architecture for you to simply maintain. You’ll shape the team’s technical direction and the products we build. - You'll work closely with engineering, product and AI research to turn ambiguous problems into scalable systems, and you'll see the impact of what you build directly. ## What you’ll be doing in the role - Build a platform to support evaluating and fine-tuning agents - Take prototypes to production; turn experiments and research ideas into reliable, well-tested software - Own what we ship as it scales in production - Solve hard problems around data, compute, orchestration, scaling, security and reliability - Work with emerging agentic AI technologies and rapidly evolving models - Make effective product and technical decisions in a highly experimental environment - Partner closely with customers, product engineering and AI research to turn problems and opportunities into working products - Drive direct impact in a fast-moving, high-ownership, cross-functional team ## What you’ll bring to the role - A background in Software Engineering, Data Engineering or MLOps - Strong experience building scalable infrastructure or distributed systems in the cloud - Solid understanding of how systems are deployed, scaled and secured - Experience applying good engineering practice and raising the bar for those around you - Hands-on experience with integrating and evaluating AI models or agents - Interest in how AI agents are trained, evaluated and improved - A product mindset with a focus on delivering business and customer value - Comfort with ambiguity, and the ability to move quickly from idea to working system - Python experience is useful but not essential ## Key Technologies - Cloud Platforms: Google Cloud Platform - Programming Languages: Python, JavaScript, and TypeScript - Frameworks: FastAPI, Vue.js, Container-based and Serverless architectures - Databases: PostGres SQL - DevOps and Monitoring: GitHub Actions, Kubernetes, Datadog, Langfuse 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. Links to more information on Prolific [Benefits](https://www.notion.so/prolific/dbc97f2b3ff24f1bb6fa834a2c9c3283?v=4f874e88e46a4f54afd8bf62f1db19ed&p=9f2c1de05dfa43338d48c20362bfead1&pm=c) [External Handbook](https://www.notion.so/prolific/dbc97f2b3ff24f1bb6fa834a2c9c3283?v=4f874e88e46a4f54afd8bf62f1db19ed) [Website](https://www.prolific.com/) [Youtube](https://www.youtube.com/@JoinProlific) Privacy Statement By submitting your application, you agree that Prolific may collect your personal data for recruiting and global organisation planning. Prolific's[Candidate Privacy Notice](https://www.notion.so/prolific/Policy-Privacy-Notice-for-Candidates-f94a136a67544388b4888bc436451b57) explains what personal information Prolific may process, where Prolific may process your personal information, its purposes for processing your personal information, and the rights you can exercise over Prolific use of your personal information. ## About Prolific ## Company Overview - **One-liner**: Prolific is a technology company that provides a platform for collecting high-quality, human-derived data from verified participants, used by AI developers, researchers, and organizations for AI training, surveys, and user research. - **Entity Type**: Private (Series A) - **Headquarters**: London, UK (with a New York City hub and remote presence across the US and UK) - **Founded**: 2014 - **Founders**: Phelim Bradley, Ph.D. (CEO & Co-founder) ## Core Business - **Primary industry/industries**: AI data services, market research, academic research, human-in-the-loop AI - **Target customers**: B2B — AI developers, academic researchers, product teams, and enterprise organizations (35,000+ data collectors use the platform) - **Mission or purpose statement**: "To help thinkers, creators, and innovators make the impossible possible" by building a future where human insight drives breakthroughs in science, technology, and society. ## Products & Services - **Prolific Platform**: A web-based platform that connects researchers and AI developers with a pool of 200,000+ active, verified participants for online studies. Studies launch every 2 minutes, with a 97% completion rate and data sets delivered in under 2 hours on average. - **AI Training & Evaluation**: Human feedback from representative populations for preference tuning, safety evaluations, and benchmarks. Used to defend AI model quality. - **Research Services**: Accelerated research through insights from verified participants, supporting behavioral research, surveys, and user testing. - **Participant Marketplace**: A paid participant side where individuals can join paid online studies with flexible scheduling and real payouts. ## Market Standing - **Valuation/Market Cap**: Not publicly disclosed - **Key Metric**: $32 million in Series A funding (secured in 2023) - **Notable Investors/Partners**: Series A funding of $32M (lead investors not specified in available data); trusted by thousands of organizations including cutting-edge AI startups and Ivy League universities. - **Growth Signals**: - Expanded into the US with a New York City hub (announced February 2024) - 172 open job listings across multiple departments (as of mid-2026) - 700+ studies launch every day on the platform - Participants from 38+ countries speaking 80+ languages - 10,000+ organizations use Prolific - 35,000+ data collectors use the platform ## Competitive Advantages - **Verified participant pool**: All participants are actively vetted, verified, and fairly paid, ensuring high-quality, trustworthy data without the noise of typical survey platforms. - **Speed and reliability**: Data sets are delivered in under 2 hours on average, with a 97% study completion rate — a significant moat for time-sensitive AI and research projects. - **Representative populations**: Ability to source diverse, representative participant pools for AI safety evals and benchmarks, critical for regulatory compliance and model defensibility. - **Trusted brand**: 10 years of operation, trusted by leading academics, AI developers, and Ivy League universities. ## Strategic Focus - **AI and human data**: Continuing to build the "biggest pool of human-derived data in the world" with a focus on powering AI training, safety evaluations, and benchmarks. - **US expansion**: Opening a New York City hub and hiring across the US (San Francisco, Seattle, New York) signals a major push into the North American market. - **Product development**: Active hiring for product, engineering, data science, and AI research roles indicates ongoing platform innovation and scaling. - **Enterprise growth**: Hiring for Strategic Customer Success Managers, Solutions Engineers, and Strategic Account Executives suggests a focus on enterprise and strategic accounts. ## Why Work Here - **Remote-first culture**: Prolific is remote-first with flexible work arrangements. Employees report high satisfaction with working location freedom (FlexScore data). Regular company-wide and team meet-ups, plus an annual in-person get-together. - **Autonomy and flexibility**: 81% of employees feel they have complete autonomy over their work; 83% are happy with flexible hours; 78% report good work-life balance. - **Benefits**: Home office budget for new joiners with annual top-up, personal learning and development budget, share options, and competitive benefits (86% employee satisfaction with benefits). - **Diversity and inclusion**: Strong DEI focus with a formal Diversity, Equity and Inclusion Monitoring statement; a culture that celebrates differences and removes barriers. - **Growth opportunity**: Join a fast-scaling business backed by $32M in Series A funding with a clear mission and strong product-market fit. - **Culture principles**: "We care deeply about our customers," "We embrace change," "We aim high," "We win together," "We make every minute count," "We are optimistic and find a way." - **Hiring process**: Structured 4-stage process (talent call, hiring manager interview, panel interview with task compensation, final principles interview) with feedback surveys to continuously improve. ## Sources 1. [prolific.com](https://www.prolific.com/) 2. [prolific.com/about](https://www.prolific.com/about) 3. [prolific.com/careers](https://www.prolific.com/careers) 4. [job-boards.greenhouse.io/prolific](http://job-boards.greenhouse.io/prolific) 5. [linkedin.com/company/prolific-com](https://www.linkedin.com/company/prolific-com) ## Other roles at Prolific - [Research Consultant](https://feeny.ai/job/research-consultant-prolific-new-york-kvj474y16hyf) — New York, NY - [Research Consultant](https://feeny.ai/job/research-consultant-prolific-united-states-qe1whh47jhc8) — United States - [Cloud Platform Engineer](https://feeny.ai/job/cloud-platform-engineer-prolific-united-kingdom-j7bxmh1wgx02) — United Kingdom - [Senior Product Engineer](https://feeny.ai/job/senior-product-engineer-prolific-new-york-jmrh4e7bm51f) — New York, NY - [Human Data Operations Partner, Research](https://feeny.ai/job/human-data-operations-partner-research-prolific-united-kingdom-ak5k0nqnspvf) — United Kingdom - [Senior Human Data Operations Partner, AI](https://feeny.ai/job/senior-human-data-operations-partner-ai-prolific-north-svjwjwb98q4z) — North, United States - [Strategic Projects Lead, Managed Services](https://feeny.ai/job/strategic-projects-lead-managed-services-prolific-united-states-2syba5k9xwtf) — United States - [Senior Human Data Operations Partner, AI](https://feeny.ai/job/senior-human-data-operations-partner-ai-prolific-mexico-nqkpva2xh12p) — Mexico - [Senior Human Data Operations Partner, AI](https://feeny.ai/job/senior-human-data-operations-partner-ai-prolific-united-states-zk6ag2nh2nkm) — United States - [Senior Product Engineer II](https://feeny.ai/job/senior-product-engineer-ii-prolific-united-kingdom-gn9294t98335) — United Kingdom