Founding Engineer, SWE

San Francisco, CA · On-site · Full-time
Compensation: $150,000–$200,000 + 0.5%–2% equity

About the Company

Our client is an early, seed-stage startup building data infrastructure and reinforcement learning environments that leading AI labs use to train and evaluate their models. Their platform lets AI teams spin up custom evaluation datasets and annotation pipelines from plain-English descriptions, automating interface generation, instructions, QA, and annotator management. They're well-backed by top-tier investors and led by a founding team out of leading AI and technology companies.

Founded 2025 · 1–10 people · Industry: AI Tools

The Role

A founding engineering role on a lean team, reporting directly to the CEO. You'd own large technical pipelines end-to-end, translating ambiguous requirements into shipped systems while balancing speed and reliability as the company scales.

What you'll be doing

• Own large scopes of technical pipelines from research through execution
• Build and scale production-grade backend and full-stack systems
• Help set technical direction alongside the CEO
• Make system-design and scalability decisions as the product grows
• Pick up new languages and tools as the work requires

Requirements

• Solid computer science fundamentals and strong engineering craft
• Hands-on experience shipping production-grade backend or full-stack systems
• Strong system-design instincts and a real grasp of scalability tradeoffs
• Comfort owning ambiguous problems end-to-end — research, tradeoff analysis, and delivery — without heavy hand-holding
• A clear communicator with a strong ownership mentality

Nice to Haves

• Time spent at startups or fast-scaling companies
• Exposure to applied AI or AI research, ideally in post-training
• Background at a reinforcement-learning-environment company or applied AI lab

Why Join

• A founding engineer seat with genuine end-to-end ownership and a direct line to the CEO
• Work that plugs straight into how modern AI models are trained and evaluated
• Early-stage momentum with strong backing and room to shape the technical direction

Details

• Location — San Francisco, CA
• Work policy — On-site
• Compensation — $150,000–$200,000 + equity
• Visa sponsorship — Available (O-1, OPT)
• Employment type — Full-time