Founding Engineer

⚠️ 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.

Why this role exists

We're in the middle of an AI war. Every week a new agent ships. The companies that win are the ones with taste: knowing what to copy, what to ignore, what to fight for, and what to ship before it's perfect. That judgment, bolted onto the ability to actually build it yourself (and fast), is the single most important skill right now. We need one person who embodies that.

The role

A founder-type IC who pulls a team along by force of shipping velocity and taste. Decides what to build, watches the competition, makes the hard simplification calls (“we don't need this, cut it”), ships it themselves or pairs to ship it in days. The team watches and absorbs the standard. Pace by example.

A senior engineer takes a spec and builds it well. This person picks the spec.

Shu Ding at Vercel set the engineering standard for the whole company through IC output alone. The engineers behind AutoGPT and BabyAGI saw the agent wave before anyone else and just built. The early Cursor team shipped an AI-native editor while everyone else debated architecture. That energy.

What you'll do

• Ship production features in your first week.

• Watch the competitive landscape daily. Know what to copy, what to ignore, what to invent.

• Make the simplification calls. “We don't need this. Cut it. Ship without it.”

• Pair with engineers to unblock them. Through code, not architecture docs.

• Care about what the user actually experiences. Every stuck conversation, every confusing flow, every extra click.

• Push back when “this is incredibly difficult and can't be estimated” is used as a reason to stall. Everything can be scoped down.

The profile

• Built and shipped an AI product to real users. Something people used and came back to.

• Deep in the agentic AI space: agents, tool use, memory systems, autonomous workflows. Has opinions about what works and what's hype.

• Writes production code at speed. Comfortable with our stack or can learn it in days.

• Product taste: looks at a user flow and knows what's wrong without being told.

• Zero ego about code quality vs. shipping speed in the current phase.

• Senior enough to push back on architecture decisions when they're blocking shipping. (Seniority measured in output and judgment, not years.)

• Founder energy: doesn't wait for specs, sees gaps and fills them. Has probably started something — YC founder, failed startup, side project with real users.

• Can context-switch. Monday: debugging a sandbox reliability issue. Tuesday: redesigning an onboarding flow. Wednesday: evaluating whether to build or buy a billing integration.

Who won't thrive here

• People who need a spec before they start building.

• People who optimize for code elegance over shipping speed at this stage.

• People who want to manage. We have managers.

• People who want to learn AI. You're already deep or you're too late.

Stack (for context, not as a filter)

TypeScript, Cloudflare Workers, Durable Objects, Hono, Drizzle ORM, Postgres, Zod, SST, Vercel AI SDK, Docker, React, Vite. If you're strong enough to be this person, the stack won't slow you down.

Compensation & Benefits

Base salary: $200K–$350K + founding-level equity + health, dental, 401(k), considerable PTO, gym budget, lunch.

Why Sauna

• $30M seed. No fundraising pressure. Just build.

• 15-person team that ships. Small enough that your decisions move the whole product.

• 2025 was vibe coding. 2026 is vibe doing. The race for the knowledge work layer is still early.

• Founding engineer equity. If this works, it's life-changing.

• The team is good. Smart, direct, low-ego. Say what you think, skip the politics.

How to apply

Send an email to [email protected] with:

• Something you built. A link, a repo, a demo.

• One paragraph on what you'd change about Sauna after trying it (sign up at sauna.ai).

• Your honest take on where the AI agent space is going in 12 months.

No cover letters. No recruiters.