Software Engineer I, RLE

About Handshake

Handshake 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 now:

• Shape how every career evolves in the AI economy, at global scale, with impact your friends, family and peers can see and feel
• Partner hand-in-hand with world-class AI labs, Fortune 500 partners and the world's top educational institutions
• Work together with engineers, scientists, operators, and more from Palantir, Meta, Scale AI, and former YC founders
• Build a massive, fast-growing business with billions in revenue

About Handshake AI

Human 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 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