Senior Platform Engineer — In‑Person (SF/Presidio)

Sauna; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Health insurance

Dental

401(k)

Equity

Lunch

Job summary

Sauna by Wordware in San Francisco (Presidio) seeks a senior backend engineer to build and own the runtime that coordinates sessions across tools and calendars. You will decide when work should be modeled as actors or jobs, and ensure long-running processes deploy smoothly through code changes.

This is a hands-on, production role with ownership from day one. The ideal candidate has shipped stateful backends, debugged concurrency and retries, and is proficient in TypeScript.

Qualifications

• Experience building production-grade backends.
• Explain decision between an actor, a background job, or a simpler service, and show what you shipped.
• You've debugged concurrency, retries, or recovery in code you've owned.
• You're productive in TypeScript and want to keep writing code as your scope grows.

Responsibilities

• Build the runtime that starts agent work and carries session state through tool calls.
• Implement choice between actors and jobs and verify behavior with overlapping sessions.
• Design how long-running processes drain or resume when code changes across releases.
• Handle retries and timeouts around tool calls, including when action succeeds but response is delayed.
• Make runtime failures traceable and fix execution paths to production.

Skills

Stateful backends

Concurrency debugging

TypeScript

System design

Tools

TypeScript

Cloudflare Workers

Durable Objects

Postgres

Docker

Job description

Sauna by Wordware in San Francisco (Presidio) seeks a senior backend engineer to build and own the runtime that coordinates sessions across tools and calendars. You will decide when work should be modeled as actors or jobs, and ensure long-running processes deploy smoothly through code changes.

This is a hands-on, production role with ownership from day one. The ideal candidate has shipped stateful backends, debugged concurrency and retries, and is proficient in TypeScript.