Senior Product EngineerTT

Were looking for a Senior Product Engineer to own the product surface of an AI assistant used in peoples everyday work tools. Youll lead the frontend architecture and user experience turning rough ideas into polished high-performance features that ship quickly. Frontend is the core of this role: React and TypeScript with a strong focus on state management rendering performance and real-time streaming interfaces. Youll also own features end-to-end from API routes and database migrations to the UI and analytics. There are no rigid PRDs or finished Figma files here so youll use your own product judgement to decide what to build and how it should feel. Its a great fit for a senior engineer with startup DNA strong product taste and a portfolio of shipped work theyre proud to show.

Details:
Schedule: Full time
Location: San Francisco United States (Onsite; candidates based in Europe who are open to relocating are welcome)
Start: ASAP
Duration: Long-term
English: Fluent
Type of collaboration: Internal Employment

About the project: The company is an early-stage San Francisco-based AI startup building an autonomous assistant for knowledge workers. The assistant connects with the tools people use every day such as Slack Gmail and Linear to automate workflows and even build small custom apps. The team is about 20 people and most engineers come from small AI-native startups several of them as founders or founding engineers. The product is AI at its core not an add-on so the frontend has to handle complex real-time and streaming experiences with a very high bar for quality. Engineers work with a lot of autonomy and are trusted to take ideas from concept to production quickly. This is a chance to shape the main product experience of a fast-moving AI company at an early stage.

You have:

• Deep expertise in React and TypeScript including state management and rendering optimization; frontend is your strongest craft
• Experience at an AI-native company (where AI is the core product) or at a top-tier product startup on the level of Notion or Linear
• A track record of shipping and owning complex web products such as multiplayer apps large-data applications or streaming/real-time UIs
• Experience owning features full-stack including API routes database migrations UI and analytics
• Public evidence of your work: a personal site a shipped product with real users a substantial public repository or a named contribution to a real design system
• At least one startup role in your career with real ownership over what you built
• Strong product sense and comfort shipping without detailed PRDs or Figma files
• Willingness to work on-site in San Francisco (or relocate from Europe) and to complete a one-week paid trial as part of the process
• Nice to have: experience as a founder or founding/early engineer at an AI agent or AI tooling startup
• Nice to have: an AI-native way of working e.g. daily use of Claude Code Cursor or Windsurf or experience with the Vercel AI SDK agent runtimes or MCP servers
• Nice to have: experience building local-first clients with TanStack Query and IndexedDB
• Nice to have: background at design-first product companies such as Figma Canva or Pinterest

What to do:

• Own the product surface of the AI assistant from frontend architecture to overall user experience
• Take rough product ideas and ship first versions quickly then iterate based on real usage
• Design and build high-performance React/ interfaces including streaming real-time and data-heavy views
• Define caching invalidation and optimistic-update strategies that keep the app fast and reliable
• Build features end-to-end across API routes database migrations UI and analytics
• Set a high bar for UI architecture code quality and developer experience across the frontend
• Work closely with founders and the wider team to shape product direction and priorities
• Use AI tools in your daily workflow and help push how the team builds with them