Senior Product Engineer - AI Startup

We’re recruiting for an **early\-stage AI startup** building an autonomous assistant that connects with everyday tools such as Slack, Gmail and Linear to automate workflows and help users build mini\-apps. The team is small, highly technical, and product\-focused. They’re looking for a **Senior Product Engineer** who can take ideas from rough concept to fully shipped, high\-performance product experiences. What you’ll be doing * Own the frontend architecture and user experience of the product * Build complex, high\-performance web experiences using **React, Next.js and TypeScript** * Develop real\-time, streaming and data\-intensive interfaces * Own features end\-to\-end, including frontend, API routes, database changes and analytics * Make architectural decisions around state management, caching, invalidation and rendering performance * Turn loosely defined product ideas into working, polished features * Work closely with a small team where engineers have significant ownership What we’re looking for * Strong professional experience with **React, Next.js and TypeScript** * Deep frontend architecture and engineering expertise * Experience building and owning **complex web products**, such as real\-time, streaming, multiplayer or large\-data applications * Experience owning features across the stack, not just frontend implementation * Strong product sense and the ability to work from broad ideas rather than highly structured specifications * **Startup experience** — candidates should have worked in an early\-stage or startup environment at some point in their career * Experience at an **AI\-native company**, where AI is central to the product, **OR** exceptional experience at a product\-focused startup comparable to companies such as Linear, Notion, Figma or Vercel * At least **3 years of commercial experience after completing your highest level of education** * A publicly inspectable portfolio, GitHub, shipped product or other evidence of your work Nice to have * Experience with AI agents, LLM applications or AI developer tooling * Experience with Vercel AI SDK, agent runtimes or MCP * Experience with **TanStack Query** and local\-first architectures * Experience using AI coding tools such as Claude Code, Cursor or Windsurf * Experience as a founding engineer or early engineering hire * Experience building products used by real customers Important This is a **fully on\-site role in San Francisco**. Candidates currently based in Europe may be considered if they are genuinely open to relocating to San Francisco. Work authorization and sponsorship requirements will be discussed early in the process. The interview process includes a **one\-week working session/trial assessment**. **Interested?** Please apply with your CV and, where available, a link to your **GitHub, portfolio, personal website or shipped product**. Public examples of your work are highly valued for this position. Pay: $180,000\.00 \- $240,000\.00 per year Work Location: In person