Senior AI Backend Engineer - San Francisco, CA (In-Person)

We're hiring a Senior AI Backend Engineer who will own the backend infrastructure behind multimodal AI agents running in real enterprise environments. This is a hands-on role where distributed systems meet applied AI: you'll build the services that take in messy real-world data, orchestrate agent workflows, keep enterprise data secure, and deliver reliable results at scale. You'll own your area end to end from day one. What you'll do Design, build and deploy backend services end to end, from data ingestion and storage to API design, background processing and deployment Build AI orchestration pipelines that hold up against real-world variability, using structured outputs, tool calling, state management and guardrails Define the orchestration patterns and evaluation frameworks the team works from, including evals and regression tests so model changes ship with confidence Set technical direction for your subsystems: own the roadmap and decide when to pay down tech debt and when to push forward Build for enterprise security: least-privilege access, tenant isolation, auditability and safe data handling Work with product, design and frontend engineers to turn loose product ideas into concrete technical plans Mentor earlier-career engineers through code reviews, architecture guidance and technical writing You may be a fit if You have 4+ years of designing and shipping production backend systems, with real architectural ownership You've designed services from scratch that other engineers now build on in production You've shipped AI-powered features to production and have your own opinions on orchestration patterns, evals and how these systems fail at scale You're comfortable setting direction and owning a roadmap rather than working from a predefined spec You're mostly backend (around 80% or more) but happy to work across the stack when needed You can work from the San Francisco office 4 days a week (Wednesday is flexible) Nice to have Experience at both large, high-caliber companies and fast-moving startups A founder or founding engineer background A degree in CS, math, physics, statistics or another highly technical field You build with AI tools every day and can help the team move faster with AI-assisted workflows What we offer Competitive compensation plus equity Fully covered medical, dental and vision Visa sponsorship (H-1B, O-1, OPT) and relocation support to the Bay Area Learning and wellness budgets Daily catered meals at the office