Senior Platform Engineer

San Francisco. Posted a month ago

The role

You will build and improve the execution engine and runtime for agent sessions. This involves managing session state, designing long-running processes, and handling retries and timeouts.

What you will do

Build and improve the runtime that starts agent work, carries session state through tool calls, and resumes interrupted runs.
Choose between actors and jobs for different kinds of work.
Design how long-running processes drain or resume when code changes.
Handle retries and timeouts around tool calls.
Make runtime failures traceable.
Find why a run stopped or stalled, fix the execution path, and see the change through to production.

Required qualifications

Built and operated stateful backend systems in production, including work that outlasts the request that started it.
Can explain a decision made between an actor, a background job, or a simpler service, and show what was shipped.
Debugged concurrency, retries, or recovery in code owned.
Productive in TypeScript.

Nice to have

Worked on an agent runtime or agent harness.
Worked with Cloudflare Workers, Durable Objects, or another actor-based runtime.
Deployed long-running processes that persist or resume work across a code release.

Benefits

health
dental
401(k)
considerable PTO
gym budget
lunch

Before you apply

Must be based in the Bay Area or willing to relocate before starting.
Require US work authorisation, but open to O-1 or J-1 visa sponsorship for exceptional candidates.
Process includes a paid work trial.

About the company

Sauna is a hybrid of AI and software standing on one shared brain. Wordware is the team behind it, 15 people backed by Spark Capital, Felicis, and Y Combinator.