Software Engineer

Pronexus is hiring on behalf of a frontier AI company for a Software Engineer to join a lean, highly technical team building core infrastructure for the next generation of agentic AI.

This is a high-ownership role for a strong generalist who enjoys solving first-principles engineering problems and building meaningful systems end to end. You will help create a complex, interconnected digital environment that enables AI models to learn, act, and interact inside a simulated world.

In this role, you will build software replicas from the ground up and integrate them into a broader world engine used by AI agents. You will develop services that maintain coherence across that environment, solve unusual systems problems that do not fit neatly into existing engineering patterns, and help build the infrastructure needed to support a rich, dynamic simulation layer.

You will work closely with a small, highly technical team and collaborate directly with researchers pushing the boundaries of modern AI. This is a full-time, on-site role based in San Francisco. Compensation is $185,000-$235,000 base plus equity. Visa sponsorship may be available on a case-by-case basis.ronexus is hiring on behalf of a frontier AI company for a Software Engineer to join a lean, highly technical team building core infrastructure for the next generation of agentic AI.

- 5+ years of software engineering experience

- Strong engineering fundamentals, ideally including TypeScript, React, and Python

- Experience shipping user-facing features end to end

- Comfort working across the stack in a high-ownership environment

- Ability to solve novel technical problems using first-principles thinking