Founding Backend Engineer

ABOUT THE ROLE As a founding backend engineer at an early-stage AI assistant company, you will own the reliable systems that power an AI agent communicating through text, email, and phone. This hands-on role spans designing, building, operating, and improving the backend infrastructure that keeps messages and scheduled actions working dependably. WHAT YOU'LL DO - Design and operate messaging pipelines for inbound and outbound communications, with reliable ordering, retries, and delivery. - Build the background agent runtime, including concurrency, timeouts, cancellation, and recovery from model or tool failures. - Develop scheduling systems that execute deferred actions reliably and in the correct time zone. - Use capacity planning, load testing, database optimization, and architectural improvements to prepare systems for growth. - Maintain secure data practices, including credential encryption, Postgres schema design and migrations, and privacy-related deletion workflows. - Build observability and cost tracking that trace messages through downstream model and tool calls. - Set backend engineering standards and help recruit and mentor future team members. WHAT WE'RE LOOKING FOR - At least 4 years of software engineering experience, including substantial production on-call responsibility. - Deep distributed-systems experience with queues, workers, retries, idempotency, and production failure modes. - Experience scaling production systems through rapid growth and making sound architectural tradeoffs. - Production experience with Postgres, including schema design, migrations, and performance tuning, as well as cloud infrastructure and infrastructure as code. - Production experience with TypeScript or Python. - Experience building messaging, telephony, or event-driven systems where dropped or duplicated events have meaningful consequences. - Experience with observability, tracing, capacity planning, and measuring latency and cost across distributed systems. - A hands-on approach to technical leadership, plus the ability to verify and own code produced with AI-assisted development tools. COMPENSATION & BENEFITS Base salary: $200,000 to $300,000 annually. Visa sponsorship is not available. LOCATION Full-time, on-site in San Francisco, California.