Full-Stack Software Engineer, Reinforcement Learning

HUD is building infrastructure to create RL training data and evals for frontier AI agents as well as a marketplace to sell these to frontier labs through the HUD marketplace. Our platform is used by frontier labs Fortune 500 companies and startups. Weve raised $16M from top VCs and were YC W25.

Were looking for a Full-Stack Software Engineer Reinforcement Learning to build the product surfaces backend systems and internal tools that power HUDs RL data engine.

Youll own product surfaces end-to-end including backend services APIs databases dashboards tools vendor workflows data collection and observability for RL rollouts. You dont need to be a researcher but you need to work research engineers and vendors to translate ambiguous needs into polished products that enable our RL systems.

• Develop product-facing tools for browsing environments inspecting trajectories reviewing task quality debugging failures and understanding model behavior

• Build vendor-facing workflows that make it easy for external partners to create submit test and iterate on RL environments and training data

• Create dashboards and observability tools that surface environment quality eval results data collection progress grader issues reward signal problems and pipeline health

• Design backend services and APIs that connect task authoring data collection evaluation QA/QC and RL training infrastructure

• Partner closely with research operations and GTM teams to turn vague high-stakes requests into well-designed systems that ship quickly

You may be a good fit if you have:

• Strong software engineering fundamentals and real full-stack range including proficiency in Python and a modern web stack such as React TypeScript or similar

• Experience owning user-facing or internal products end-to-end

• Good product taste and the ability to build tools that are intuitive for both technical and non-technical users

• Comfort with cloud infrastructure Docker CI/CD observability and production debugging

• High agencyyou identify what needs to exist build it and improve it without waiting for a perfect spec

• Strong communication skills for working across research engineering operations vendors and founders

Strong candidates may also have:

• Experience building data collection labeling annotation eval or research tooling platforms

• Experience building dashboards review workflows observability tools or debugging interfaces for complex systems

• Experience building developer tools infrastructure products internal platforms or workflow products that made a team dramatically faster

• Experience with AWS Kubernetes Terraform Docker Grafana or similar infrastructure tools as tools to ship product not as the center of the role

We prioritize technical aptitude and learning potential over years of experience. Motivated candidates are encouraged to apply even if they dont meet all criteria.

• Team Size: 25 people currently mostly full-time in-person but some remote.

• Our team: Our team includes 4 International Olympiad medalists (IOI ILO IPhO) serial AI startup founders and researchers with publications at ICLR NeurIPS etc.

• Company stage: We have 8 figures in funding and are scaling profitably and quickly to meet very strong demand.

• Employment: Full-time.

• Location: We have offices in San Francisco or Singapore but are open to remote candidates who can work hours that 70-80% overlap with either San Francisco or Singapore time zones.

• Visa Sponsorship: We provide support for relocation and visas for strong full-time candidates to the US or Singapore.

• Timeline: Applications are rolling. The process is 2 technical interviews and a 2-3 day work trial.

• Competitive compensation

• 100% covered top-of-the-line medical dental and vision from Blue Shield of CA (US employees)

• Lunch and dinner when youre in the office (in-office employees)

• Company-wide holiday break (Christmas Eve to New Years Day) on top of PTO and paid holidays

• Other perks including an Equinox membership 401k and commuter benefits (US employees)

• Unlimited* access to tokens for ChatGPT Claude Code Cursor etc. *By unlimited we mean no one on our token usage leaderboard has ever hit a limit. So we have no idea what the limit is.

Due to high volume we may not actively respond to every application but feel free to contact us at or elsewhere if we missed your application!

Required Experience:

IC