At a Glance
- Tasks: Design and develop cutting-edge RL environments using real human behavioural data.
- Company: Join a pioneering AI startup with significant funding and ambitious goals.
- Benefits: Competitive salary of £300,000 plus founding equity and remote work options.
- Other info: Limited positions available; apply now to secure your spot in this dynamic team.
- Why this job: Be at the forefront of AI innovation and make a real impact in the industry.
- Qualifications: Experience in building RL environments and a passion for solving complex AI challenges.
Remote | London / Paris preference but EU based a must | £300,000 + founding Equity
The best AI engineers aren't waiting for a job ad. They're waiting for the right moment. This might be it. Anthropic leadership has discussed spending over $1 billion on RL environments in the next year alone. The market is moving - fast and at scale. One pre‑seed company just closed a round at a valuation most Series A companies would envy, with frontier AI labs already as paying clients and acquisition interest already on the table. The reason? They cracked something the rest of the market hasn't.
Most teams build RL environments from synthetic data - easy to demo, easy to commoditize, brittle. This team mines real human behavioural data - how domain experts actually reason, decide, and solve complex tasks over long-horizon workflows. 10‑100+ step environments. Closed‑loop systems where environments, data, training, and evaluation are tightly integrated. Not proxies. Not shortcuts. 25‑30% uplift in model task success rates. 50‑65% more training signals. Evals that reflect how humans actually work. The funding just landed. Second time founders. The founding team is being built right now. There are very few seats. Are you going to be in one of them?
£300,000 + founding equity at a ~$30M pre‑seed valuation. Frontier AI labs as paying clients from day one. Environment design treated as a first‑class problem - not an afterthought. London / Paris hybrid with remote options. Get in now - before this role disappears and you're watching from the outside.
You’ll love this if...
- You’ve built RL environments, gyms, or training infrastructure at a serious RL or AI company
- You think environment design & the lack of data available are the most underrated problems in AI right now
- You move fast, think in first principles, and thrive without a playbook
- You want to work at the forefront of innovation with frontier labs
Roles like this don't stay open. If it fits – apply today. Because great teams are Built Different.
Research Engineer employer: BUILT DIFFERENT
At Anthropic, we pride ourselves on being an exceptional employer, offering a unique opportunity for Research Engineers to work at the cutting edge of AI innovation. With a competitive salary of £300,000 plus founding equity, our remote-friendly culture allows for flexibility while fostering collaboration between our London and Paris teams. We are committed to employee growth, providing access to pioneering projects and a chance to shape the future of AI in a supportive and dynamic environment.
