Member of Technical Staff, Platform Engineering

This role is being recruited by CoffeeSpace on behalf of an anonymous venture-backed AI startup building reinforcement learning environments and infrastructure for frontier AI systems in financial services. We’re identifying a small number of exceptional platform and full-stack engineers from our network. If there’s a strong fit, we’ll introduce you directly to the founding team. Location: San Francisco, CA Compensation: $200K–$250K base + 0.15%–0.3% equity Employment type: Full-time Work setup: 5 days in-office Visa: Open to visa transfers, including OPT and H-1B transfers About the company This company builds reinforcement learning environments and benchmarks used to train and evaluate advanced AI agents for financial services workflows. They work with frontier AI labs and financial institutions on domains like investment banking, private equity, hedge funds, Excel modeling, and other complex computer-based tasks. The company has raised $8.5M, is still a small early-stage team, and is scaling quickly as demand for high-quality RL environments grows. About the role As a Platform Engineer, you’ll help build the infrastructure, tooling, and environments used to train and evaluate frontier AI agents. You’ll work across platform engineering, ML infrastructure, synthetic data, evaluation systems, and product development, with meaningful ownership from day one. What You’ll Do Build scalable training and inference infrastructure for RL environmentsDevelop realistic, long-horizon environments for frontier AI agentsBuild software that increases the quality and throughput of environment creationDesign synthetic data pipelines and domain-specific verifiersCreate internal platforms and analytics for managing costs, workflows, and bottlenecksWork directly with engineers, customers, and subject-matter experts Outcomes Scale infrastructure supporting production RL environmentsMake environment creation dramatically faster and more reliableImprove the realism and difficulty of agent benchmarksBuild robust verifier and reward systems for financial workflowsEstablish strong engineering systems as the company growsHelp the team deliver high-quality environments to major AI labs and financial institutions Why This Role Is Compelling Work directly on frontier AI training and evaluation infrastructureBuild RL environments used for complex real-world financial workflowsJoin a small team with significant ownership and early-stage equityWork with major AI labs and financial institutionsOperate across platform engineering, AI infrastructure, and productReceive strong benefits including healthcare, relocation support, meals, transportation, and 401(k) matching The Ideal Candidate 3–8 years of platform, backend, or full-stack engineering experienceExperience at an early-stage startup or as a former founderStrong Python, TypeScript, infrastructure, and systems engineering fundamentalsExperience building ML tooling, AI agent platforms, evaluations, benchmarks, or RL environmentsComfortable shipping quickly and owning projects end-to-endStrong interest in AI, with financial services experience a plus Next steps Apply via this LinkedIn job postWe’ll review and reach out if there’s a strong matchIf aligned, we’ll introduce you directly to the founding teamIf this role isn’t the right fit, we may suggest and make introductions to other high-signal startup roles we’re recruiting for, always with your permission. A quick note on authenticity This is a real, active role that CoffeeSpace is recruiting for in close partnership with the hiring team. We don’t post speculative roles and work directly with teams on their actual hiring needs.