Founding Engineer at $6M Seed AI infrastructure startup

As a Founding Engineer at this YC S25 startup, you will build the critical identity and communication layer for the agentic era. You will design high-throughput backend systems and APIs that serve as the inbox for AI agents, enabling them to communicate and authenticate as independent digital citizens in a rapidly expanding market.

• Design and implement intuitive APIs and abstractions that allow AI agents to operate as first-class citizens of the internet.
• Build and scale distributed systems and core infrastructure capable of processing over 100 million emails per day with low latency.
• Own projects end-to-end, from initial system design to production rollout, while collaborating directly with the founding team and customers.

• Strong backend and systems engineering background with experience shipping production-grade software at a high-growth tech company or startup.
• Deep understanding of distributed systems, cloud infrastructure, or developer tools, with a preference for messaging and protocol-heavy experience.
• High-velocity builder who thrives in ambiguity and obsesses over quality, detail, and solving complex problems from 0 to 1.

• Work at the frontier of AI infrastructure with $6M in funding from General Catalyst, Paul Graham, and the CTO of HubSpot.
• Join a high-performance team of 8 hailing from NVIDIA, Amazon, and Optiver, currently doubling their user count every two weeks.
• True founding impact with significant equity and the opportunity to define a new category of the internet where agents outnumber humans.