Founding Backend Engineer

ABOUT THE ROLE Own the backend infrastructure for an AI-powered personal assistant that communicates through text, email, and phone. As a hands-on founding engineer, you will design, operate, and improve reliable systems that ensure messages and scheduled actions work as expected. WHAT YOU'LL DO - Design and operate messaging pipelines for inbound and outbound communications, with reliable ordering, retries, and delivery tracking. - Build an agent runtime for background tasks, handling concurrency, timeouts, cancellation, and recovery from model or tool failures. - Implement scheduling for deferred actions and follow-ups that must run reliably in the correct time zone. - Plan capacity, load test, optimize databases, and evolve architecture to support substantial traffic growth. - Own data security, privacy, Postgres schemas and migrations, and user data deletion workflows. - Build observability and tracing across messages, model calls, and tools, and monitor latency and cost. - Set backend engineering standards and help grow the engineering team while remaining hands-on. WHAT WE'RE LOOKING FOR - At least 4 years of software engineering experience, including production on-call ownership for systems handling meaningful traffic. - Deep experience building and scaling distributed systems, including queues, workers, retries, idempotency, and failure recovery. - Experience scaling systems through rapid growth and making sound technical prioritization decisions. - 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 and capacity planning for growing workloads. - Experience with messaging, telephony, or other event-driven systems where dropped or duplicated events have real costs. - Experience building observability and tracing that measure latency and cost across distributed components. - Familiarity with AI-assisted development workflows and the ability to verify and take responsibility for generated code. - Hands-on technical leadership, a founding-team mindset, and a record of sustained work in a role or deep expertise in a technical domain. COMPENSATION & BENEFITS Base salary is $200,000 to $300,000 annually. Equity details are not provided. Visa sponsorship is not available. LOCATION Full-time, on-site in San Francisco, California.