Founding Systems Engineer for AI Agents (Equity)

Jack & Jill; San Francisco (CA); On-site; USD 150,000 - 250,000; Full time

Job summary

General Catalyst-backed startup is seeking a Founding Engineer to design the core primitives that enable AI agents to communicate and operate as independent entities. You’ll build high-throughput email infrastructure and APIs, owning projects end-to-end for a rapidly growing user base in San Francisco.

This is a systems-heavy role at a YC S25 company defining a new infrastructure category. You’ll bridge modern AI capabilities with traditional messaging protocols to create a scalable agent

Qualifications

• Proven track record of shipping production software.
• Strong backend and systems engineering instincts for distributed systems.
• High bar for quality; thrives in fast-paced, detail-oriented environments.

Responsibilities

• Design and implement high-performance, low-latency APIs and abstractions for AI agents.
• Scale distributed systems and core infrastructure to handle growing email volumes.
• Bridge AI capabilities with email protocols to create an agent identity provider.

Skills

Backend systems

Distributed systems

Problem solving

Job description

General Catalyst-backed startup is seeking a Founding Engineer to design the core primitives that enable AI agents to communicate and operate as independent entities. You’ll build high-throughput email infrastructure and APIs, owning projects end-to-end for a rapidly growing user base in San Francisco.

This is a systems-heavy role at a YC S25 company defining a new infrastructure category. You’ll bridge modern AI capabilities with traditional messaging protocols to create a scalable agent