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.