Founding Engineer

About the role

We're creating the third layer of interaction — a personalized AI action layer that lives across all your workflows. If that excites you, and you’re a world-class infrastructure expert, please apply.

Why Dex Matters

- Flow is everything. Every tab switch, every UI reload, every wait for an AI handoff kills momentum.

- The future of productivity is collaborative AI. Dex is an active, real-time partner embedded directly in your browser—the place where your work actually lives.

- Context makes or breaks a product. You need systems that understand where you are, what you're doing, and what should happen next.

What You'll Build

- Core agent components, including memory stores, context compression, inter-agent protocols, planning and tool use.

- High performance state management and real-time UI observation systems.

- Scalable infrastructure for browser-native AI.

Requirements

- Expert in React/Next.js, TypeScript, and Python.

- Deep browser internals experience.

- Proven rapid prototype to production track record.

- Preferred: Prior experience with AI/ML infra or agentic systems.

Sample Projects

- Translating browser inputs (voice, keyboard and mouse inputs, tab changes, DOM) into actionable workflow graphs.

- Agentic systems that predict and execute users’ next steps in complex workflows.

- A searchable, self-updating memory store for personalized user flow paths.

See the posting on Thirdlayer's site