Founding Product Engineer
Fulltime
Onsite in SFO,CA
We are looking for a Founding Product Engineer with 0-7 years of experience to define what using client portal feels like for the developers building the most ambitious AI agents. You are a high-agency, full-stack builder with strong product and design instincts who has owned projects from 0 to 1 in a startup environment. Client is rebuilding email for AI, has already processed hundreds of millions of emails, and needs builders who can turn ambiguous customer problems into products developers love. You will work directly with the founders and help shape the product engineering culture from day one
3 - 7 years of experience as a product engineer or fullstack engineer
Engineering experience at a high growth startup (seed to series B)
What will you be doing?
Building products end-to-end across polished frontend experiences, APIs, backend services, data models, and infrastructure
Talking directly to developers, digging into support conversations and usage data to understand where they get stuck
Turning vague customer problems into shipped products, deciding what to build, not just how to build it
Prototyping quickly and shaping the developer experience from sign-up to production
Helping define client product engineering culture and design standards as one of the earliest engineers
Frontend Development, APIs, Backend Services, Databases, Queues, Distributed Systems, Infrastructure
What it's like to work here:
Bottom-up ownership: Work doesn't just flow down from the founders. Team members are expected to talk to users, spot problems that have measurable impact, and build the solutions themselves.
No PM specs or Figma handoffs: Engineers take part in the whole product process: user conversations, prioritization, design, code, shipping and measuring results.
Close to customers: The users are highly technical developers, so you see the impact of what you ship right away. The founders still handle support tickets and talk to users every day.
AI-first workflows: The stack is mostly TypeScript, and AI does much of the heavy lifting. The focus is on judgment, taste and product sense.
In-person and high-intensity: The team works on-site in San Francisco five days a week. It's a scrappy, fast-moving startup environment.
·Social and community-oriented: The team hosts events such as founder dinners, VC dinners and poker nights.
