Founding Backend Engineer

ABOUT THE ROLE Own the backend systems behind an AI assistant that communicates through text, email, and phone. As a hands-on founding engineer, you will design, build, and operate reliable infrastructure for message delivery, long-running agent tasks, and scheduled actions. WHAT YOU'LL DO - Design and operate messaging pipelines with reliable ordering, retries, and delivery across communication channels. - Build an agent runtime for background tasks, managing concurrency, timeouts, cancellation, and recovery from model or tool failures. - Implement scheduling for future actions, ensuring they run reliably and in the correct time zone. - Plan capacity, load-test services, optimize databases, and address bottlenecks as systems scale. - Manage data security and privacy, including credential encryption, Postgres schemas and migrations, and data deletion workflows. - Build observability and tracing to track latency and costs across messages, models, and tools. - Establish backend engineering practices and help recruit and mentor future team members. WHAT WE'RE LOOKING FOR - At least 4 years of software engineering experience, including substantial on-call ownership of production systems handling meaningful traffic. - Deep experience with distributed systems, including queues, workers, retries, idempotency, and production failure modes. - A track record of scaling systems through rapid growth and making sound decisions 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 software in TypeScript or Python and building reliable messaging or event-driven systems. - Experience with capacity planning, observability, distributed tracing, and measuring latency and costs. - Familiarity with AI-assisted development workflows and the ability to verify and take ownership of generated code. COMPENSATION & BENEFITS Salary range: $200,000 to $300,000 annually. Visa sponsorship is not available. LOCATION On-site in San Francisco, California, United States.