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

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 doDesign, build and deploy backend services end to end, from data ingestion and storage to API design, background processing and deploymentBuild AI orchestration pipelines that hold up against real-world variability, using structured outputs, tool calling, state management and guardrailsDefine the orchestration patterns and evaluation frameworks the team works from, including evals and regression tests so model changes ship with confidenceSet technical direction for your subsystems: own the roadmap and decide when to pay down tech debt and when to push forwardBuild for enterprise security: least-privilege access, tenant isolation, auditability and safe data handlingWork with product, design and frontend engineers to turn loose product ideas into concrete technical plansMentor earlier-career engineers through code reviews, architecture guidance and technical writingYou may be a fit ifYou have 4+ years of designing and shipping production backend systems, with real architectural ownershipYou've designed services from scratch that other engineers now build on in productionYou've shipped AI-powered features to production and have your own opinions on orchestration patterns, evals and how these systems fail at scaleYou're comfortable setting direction and owning a roadmap rather than working from a predefined specYou're mostly backend (around 80% or more) but happy to work across the stack when neededYou can work from the San Francisco office 4 days a week (Wednesday is flexible)Nice to haveExperience at both large, high-caliber companies and fast-moving startupsA founder or founding engineer backgroundA degree in CS, math, physics, statistics or another highly technical fieldYou build with AI tools every day and can help the team move faster with AI-assisted workflowsWhat we offerCompetitive compensation plus equityFully covered medical, dental and visionVisa sponsorship (H-1B, O-1, OPT) and relocation support to the Bay AreaLearning and wellness budgetsDaily catered meals at the office