About the job
This role is being recruited by CoffeeSpace on behalf of an anonymous AI infrastructure startup building the identity and communication primitive for AI agents.
We’re identifying a small number of exceptional founding engineers from our network. If there’s a strong fit, we’ll introduce you directly to the founding team.
Location: San Francisco, California, United States
Compensation: $150K–$250K base + 0.5%–1% equity
Employment type: Full-time
Visa: Visa sponsorship not available
About the company
This company provides email inboxes specifically designed for AI agents, similar to how Gmail provides inboxes for humans. They focus on AI, API SDK, devtools, and B2B industries. The company has raised $6M in seed funding from elite angels including Paul Graham and Dharmesh Shah. The team consists of 8 people, with 6 engineers from prestigious backgrounds such as Optiver, NVIDIA, and Amazon.
The company is experiencing hypergrowth, doubling user count every two weeks since January and achieving 20–30% month-over-month revenue growth.
About the role
As a founding engineer, you will be responsible for building and designing APIs and backend infrastructure that AI agents use to communicate, authenticate, and operate. This involves owning projects from inception to production, with a focus on backend development.
You will work across the full stack when needed, and will be expected to proactively pitch growth experiments or product ideas. Additionally, you will occasionally support enterprise customers with custom deployments and write clear, maintainable code and documentation.
What You’ll Do
- Build and design core product APIs and backend infrastructure
- Own 0→1 projects end-to-end, including customer requirements, system design, and production rollout
- Work across the full stack, primarily on backend systems
- Proactively pitch growth experiments and product ideas
- Support enterprise customers with custom deployments
- Write clear, maintainable code and strong technical documentation
Why This Role Is Compelling
- You’ll have greenfield ownership over projects, scoping, building, and shipping them
- The role is backend-first but allows exploration into growth, product, or forward deployment work
- Competitive compensation with additional perks like Equinox membership and free meals
The Ideal Candidate
- 0–5 years of experience, with flexibility for exceptional candidates with more
- Experience shipping production software at a pedigreed company
- Comfortable owning projects end-to-end in a fast-paced, early-stage environment
- Experience with TypeScript, REST APIs, distributed systems, cloud infrastructure, and email protocols
This Role Is NOT For You If
- You require visa sponsorship
- You prefer a stable, clearly scoped role without ambiguity
- You are not comfortable working on-site in San Francisco
Next steps
- 1. Apply via this LinkedIn job post
- 2. We’ll review and reach out if there’s a strong match
- 3. If aligned, we’ll introduce you directly to the team
- 4. If this role isn’t the right fit, we may suggest and make introductions to other high-signal startup roles we’re recruiting for, always with your permission.
A quick note on authenticity
This is a real, active role that CoffeeSpace is recruiting for in close partnership with the hiring team. We don’t post speculative roles and work directly with teams on their actual hiring needs.