Y Combinator Founding Engineer
Summary
Builds cross-platform terminal tools (macOS, iOS, Windows, Linux, cloud) for AI-powered coding workflows, owning full product cycles from design to user feedback.
cmux is a native macOS terminal built on Ghostty, designed for running multiple AI coding agents in parallel. Hundreds of thousands of developers use cmux to drive their agentic coding workflows.
Check us out at and on GitHub.
We're hiring talented founding engineers to help us build the future of coding with AI.
What you'll do
- Build frontier devtools across the stack: cmux macOS (Swift/AppKit), cmux TUI (Rust), cmux Windows/Linux (C++/Chromium), cmux iOS, cmux Cloud, subrouter (Go), chatmux, and more
- Help invent the most useful product for developers to do work with AI
- Own products and features end to end, including user feedback loops
- Dogfood, test, and verify constantly; use cmux to build cmux
Who we're looking for
No hard requirements. We want talented builders from any background.
Things that make us extra excited:
- You use 10B+ tokens a day
- All-rounders and creative problem solvers
- Great design taste and care for the craft
- Swift/AppKit, C++, Rust, Go, or Chromium experience
- Open-source maintainers, former founders, people who ship complete products
- Sending cmux PRs for us to review or demoing custom cmux plugins / workflows
Details
- Compensation: 130k - 170k + 0.5% - 1.5% equity
- Benefits: Health, dental, and vision insurance
- Location: San Francisco