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.