Software Engineer I, RLE at Handshake

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