About the role
Please read first
- This is a full-time, in-person role based in San Francisco (Presidio) - we work from the office 5 days a week.
- You must be based in the Bay Area or willing to relocate before starting.
- We require US work authorisation, but are open to O-1 visa sponsorship for truly exceptional candidates.
What You'll Do
You've seen what happens when systems hit scale, and you know which parts to rebuild before they break. This isn't a management role. You're the most experienced builder on the team, and the CTO's partner on every architectural decision that matters.
Sauna's architecture works today. It won't be optimal at 1000x the current load with 50x the integration surface. You'll make the calls that shape what it becomes. Here are a few examples:
- Make hard architectural tradeoffs and own the outcome: Durable Object SQLite vs. shared Postgres for session state. Cloudflare Workers CPU limits vs. longer-running workloads. Single-tenant sandboxes vs. multi-tenant pools. You decide, you migrate, you ship.
- Design the system that handles concurrent agent sessions across integrations, an agent responding to an iMessage, checking Calendar, drafting a Slack reply, and updating Linear, all within one session with consistent state.
- Define reliability and observability standards for a ~15-person team: SLOs, error budgets, tracing strategy, incident response patterns that actually work at our scale.
- Review every significant PR. Set technical direction without blocking velocity. Your pattern recognition from prior scale experience is the product.
