Founding Backend Engineer

ABOUT THE ROLE Build and operate the backend for an AI assistant that communicates through text, email, and phone. As a hands-on founding engineer, you will own systems where reliable, timely message delivery is essential and help shape the team's engineering standards. WHAT YOU'LL DO - Design and operate messaging pipelines for inbound and outbound communications, with reliable ordering, retries, and delivery tracking. - Build the background agent runtime, including concurrency controls, timeouts, cancellation, and recovery from model or tool failures. - Develop scheduling systems for future actions that must run reliably and in the correct time zone. - Plan capacity, load-test services, optimize databases, and make architectural improvements to support growth. - Own security and privacy practices, including credential encryption, Postgres schemas and migrations, and data deletion workflows. - Build observability and cost tracking that traces messages through downstream model and tool calls. - Set backend engineering standards and help recruit and mentor a growing engineering team while remaining hands-on. 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 tradeoffs about what to address immediately. - Production experience with Postgres, including schema design, migrations, and performance tuning, as well as cloud infrastructure and infrastructure as code. - Experience shipping production systems in TypeScript or Python. - Background in messaging, telephony, or event-driven systems where dropped or duplicated events have real costs. - Experience with observability, distributed tracing, capacity planning, and measuring latency and cost. - Hands-on technical leadership and familiarity with AI-assisted development workflows, including verifying and owning generated code. COMPENSATION & BENEFITS Base salary: $200,000 to $300,000 annually. Visa sponsorship is not available. LOCATION Full-time, on-site in San Francisco, California.