Member of Technical Staff, Platform Engineering

Our client is an early-stage, venture-backed AI startup building fully managed reinforcement-learning environments and benchmarks used to train computer-using agents for financial services. Their gyms teach AI agents to carry out real analyst and operator work — think spreadsheet modeling, presentation building, and trading workflows — and leading AI labs are already paying customers. They are growing fast and scaling the founding engineering team.

Founded 2024 · ~6 people · Industry: AI, Data, Financial Services, Enterprise

As a founding Member of Technical Staff on platform engineering, you will own the infrastructure behind the company's RL environments, develop increasingly realistic and long-horizon environments for frontier models, and help stand up the engineering org and its culture from scratch.

What you'll be doing

• Build the training and inference infrastructure that supports customer usage of RL environments at scale
• Research and develop next-generation RL environments that are more realistic, longer-horizon, and harder for frontier models
• Ship tooling that dramatically increases the quality and throughput of environment creation
• Design synthetic data pipelines that generate realistic problems
• Build platform analytics for environment costs, throughput, bottlenecks, and expert management
• Craft domain-specific verifiers and reward functions for financial workflows (e.g. presentation building, spreadsheet modeling, quantitative trading)
• Establish engineering practices and culture from the ground up

Tech stack: Python, TypeScript, Docker, AI coding tools; cloud (AWS, S3) a plus

• 2–8 years of platform or full-stack engineering experience, ideally building RL environments or ML infrastructure
• Time spent at an early-stage startup (pre-seed to Series A), or experience as a founder
• A track record as a platform, full-stack, or backend engineer at fast-moving, high-growth companies
• A degree in CS, ML, or a related technical field
• Demonstrated experience building scalable platforms for internal or external users (ML tooling, benchmarking, or agent products)
• A heavy user of AI coding tools who ships at high velocity
• Based in the Bay Area, or ready to relocate, and able to work on-site 5 days a week

• Big-tech experience earlier in your career before moving to a startup
• Hands-on experience building RL environments, evals, or benchmarks for AI agents
• Background in, or strong interest in, fintech or financial services
• Experience designing domain-specific verifiers or reward functions

• Frontier AI labs are already paying customers, with fast-growing revenue and momentum
• True founding ownership over platform engineering and the engineering org you'll help build
• Strong benefits for the stage: fully covered healthcare, relocation support, 401k with a 4% match, free meals, gym, and covered transportation

• Location: San Francisco, CA
• Work policy: On-site, 5 days a week
• Compensation: $200K–$250K + equity
• Visa sponsorship: Open to visa transfers (e.g. OPT, H-1B transfers)
• Employment type: Full-time