Unknown Company

Founding Engineer

san francisco, ca • Posted Today
Onsite Internship IT & Technology

A pre-seed startup in San Francisco is building the operating system for AI-native service companies: a workforce of AI agents that runs a service business's day-to-day operations end to end. The founder is a second-time founder with a prior exit who has just relocated to SF, and the company recently closed its angel round with leading operator-angels from Europe and the US.

The role

You will be one of the first three engineers, and the first ones hired. This is a CTO-calibre seat: you set the technical direction, write most of the early code, and decide what "production-ready" means for agents that run real businesses.

There are three flavours of this role, and strong candidates often span more than one:

Product-minded engineer: takes a vague customer problem to a shipped, polished product in days

Agent / LLM engineer: builds agent harnesses, tool use, evals and orchestration that hold up in production

Full-stack / infra engineer: builds the platform, data layer and reliability that let agents run at scale

What you'll do

Build the core agent platform from zero with the founder

Ship end-to-end product for the first design partners, fast

Own architecture, tooling and engineering culture as the team grows

Talk to customers directly and turn what you learn into product

What you bring

2 to 8 years of hands-on software engineering, with production systems you built yourself

Zero-to-one experience: founder, technical co-founder, CTO, or a founding or very early engineer at a high-growth startup

An unusually fast learner, with something distinctive on your profile (a company you built, a hard technical project, olympiad or competition results, a top internship)

You use AI agents heavily in your own work and have opinions about the tooling and harnesses you build

You want to build intensely: this is a 6-day, in-person team in San Francisco

Nice to have: early engineering at a top AI-native or YC startup; strong internships (quant firms, AI labs, top tech); a strong CS or engineering degree

Working here

In person in San Francisco, 6 days a week, alongside the founder

Relocation supported; O-1 visa route for exceptional international candidates (a start in Vienna before moving to SF is possible)

Competitive SF base plus meaningful founding equity; co-founder-level equity for exceptional candidates

Process: intro call with the founder, deep-dive, technical interview, close

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Founding Engineer in san francisco at Unknown Company

This position is listed as internship and onsite.

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