Software Engineer I, RLE

**About Handshake** Handshake is the career network for the AI economy. 20 million knowledge workers, 1,600 educational institutions, 1 million employers (including 100% of the Fortune 50\), and every foundational AI lab trust Handshake to power career discovery, hiring, and upskilling, from freelance AI training gigs to first internships to full\-time careers and beyond. This unique value is leading to unparalleled growth; in 2025, we tripled our ARR at scale. **Why Join Handshake Now** * Shape how every career evolves in the AI economy, at global scale, with impact your friends, family and peers can see and feel * Work hand\-in\-hand with world\-class AI labs, Fortune 500 partners and the world’s top educational institutions * Join a team with leadership from Scale AI, Meta, xAI, Notion, Coinbase, and Palantir, among others * Build a massive, fast\-growing business with billions in revenue **About The Role** We’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 Do * Build and scale core components of RLE environments and infrastructure * Design and implement backend systems and data pipelines * Translate ambiguous product and research needs into production systems * Develop modular, reusable workflow domains * Improve reliability, observability, and system performance What We’re Looking For * 2–4 years of experience in backend, distributed systems, or ML\-adjacent infrastructure * Strong proficiency in ReactJS and TypeScript * Solid experience with relational databases (PostgreSQL) and data modeling * Experience with cloud infrastructure (AWS/GCP) and CI/CD * Ability to independently drive projects from design to production Nice to Have * Experience with simulation systems or evaluation platforms * Exposure to ML systems or working with research teams * Experience in fast\-moving, operations\-heavy environments What Success Looks Like * Owns and delivers key RLE components end\-to\-end * Improves system scalability and developer velocity * Enables faster launch of new domains with high\-quality data **Perks** Handshake 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 bonuses Compensation Range: $157\.5K \- $175K