Software Engineer I, RLE

About HandshakeHandshake was founded on a simple belief that everyone deserves a path to a great career, regardless of where they went to school or who they know. Today, we power 25 million job seekers, 1 million+ employers, and 1,600 educational institutions.

In 2025, we started Handshake AI and built the fastest-growing AI data business in history. We work directly with frontier AI lab researchers to create evaluations, publish benchmarks, and push the boundary of data. We’ve grown from $0 to ~$1B run rate and pay ~$60M to over 30K individuals every month.

Why Join Handshake NowShape how every career evolves in the AI economy, at global scale, with impact your friends, family and peers can see and feelPartner hand-in-hand with world-class AI labs, Fortune 500 partners and the world’s top educational institutionsWork together with engineers, scientists, operators, and more from Palantir, Meta, Scale AI, and former YC foundersBuild a massive, fast-growing business with billions in revenueAbout Handshake AIHuman data is the core infrastructure to AI advancement. Frontier AI labs currently improve model capabilities with various data-intensive post-training techniques. We believe that data spend for AI training will increase by 3-5x in the next few years and continue for much longer as models take on new domains. Handshake AI supports all of the frontier AI labs, working on their most complex data at the largest scale.

About The RoleWe’re hiring a Software Engineer to build our Reinforcement Learning Environments (RLE) platform—the interactive systems where frontier AI models learn to complete real-world work.

This role owns meaningful components end-to-end and plays a key part in scaling systems that power model training and evaluation.

Location: San Francisco, CA (in-office, 5 days/week)What You’ll DoBuild and scale core components of RLE environments and infrastructureDesign and implement backend systems and data pipelinesTranslate ambiguous product and research needs into production systemsDevelop modular, reusable workflow domainsImprove reliability, observability, and system performanceWhat We’re Looking For2–4 years of experience in backend, distributed systems, or ML-adjacent infrastructureStrong proficiency in ReactJS and TypeScriptSolid experience with relational databases (PostgreSQL) and data modelingExperience with cloud infrastructure (AWS/GCP) and CI/CDAbility to independently drive projects from design to productionNice to HaveExperience with simulation systems or evaluation platformsExposure to ML systems or working with research teamsExperience in fast-moving, operations-heavy environmentsWhat Success Looks LikeOwns and delivers key RLE components end-to-endImproves system scalability and developer velocityEnables faster launch of new domains with high-quality dataPerksHandshake delivers benefits that help you feel supported—and thrive at work and in life.

The below benefits are for full-time US employees.🎯 Ownership: Equity in a fast-growing company💰 Financial Wellness: 401(k) match, competitive compensation, financial coaching🍼 Family Support: Paid parental leave, fertility benefits, parental coaching💝 Wellbeing: Medical, dental, and vision, mental health support, $500 wellness stipend📚 Growth: $2,000 learning stipend, ongoing development💻 Office: Commuting support, free lunch, and gym in our SF office🏝 Time Off: Flexible PTO, 15 holidays + 2 flex days🤝 Connection: Team outings & referral bonusesCompensation Range: $157.5K - $175K