Senior Platform Engineer - AI Agent Runtime

TechTree in San Francisco (Presidio) is seeking a senior backend engineer to build the agent runtime that coordinates tool calls, sessions, and long-running tasks. You will decide when work lives as an actor or a job, and shape how code changes resume in-flight processes. This role emphasizes production-grade systems, concurrency, and robust tracing, with a focus on TypeScript, Cloudflare Workers, and a durable execution model. In-person, 5 days/week in the Bay Area.