2026 Summer Research Engineer Intern

Join us in pushing the boundaries of what's possible with LLMs and browser-native AI. You'll work on cutting-edge problems in agent systems, context handling, and tool use, while collaborating directly with our research team to bring novel approaches to production.

What You'll Build

Browser agent and tool-calling multi-agent systems.
Evaluation frameworks for memory, efficiency, and accuracy.
Memory and personalization layer for workflows

Requirements

Research or work experience with RL environments, LLMs, modern AI frameworks, and/or ML.
Experience with prompt engineering strategies.
Strong foundation in Python and TypeScript.

Sample Projects

Designing and creating tool-calling environments to evaluate and benchmark agent systems
Agentic systems that predict and execute users’ next steps in complex workflows.
Mapping user paths on real world software to API functionality and action trajectories.
A searchable, self-updating memory store for continuously learning agents.
A system to interpret DOM snapshots, mouse click events, and keyboard inputs to select browser actions.
A context composer that feeds relevant info into LLM prompts based on user interactions, page content, and memory.

ThirdLayer is an applied research and product lab building the next interface for human–AI collaboration.

Our first product is Dex, an AI copilot for the browser. Think Cursor for knowledge work, optimized for speed and embedded directly where you work.

Most web agents are built for set-and-forget tasks. But real work is fluid and messy—spread across tabs, tools, and evolving decisions. Dex transforms your browser into an intelligent, multimodal workspace that understands your intent through voice, text, and action. It enhances familiar interfaces, automates tedious steps, and removes the friction of handoffs.

Beneath the surface, Dex is more than a browser agent — it’s a foundation for:

● Long-term, cross-modal memory grounded in real workflows ● A new interaction layer to replace static UI with a collaborative canvas ● Personalization: understanding how individuals approach tasks and navigate software

We're building the infrastructure for adaptive, intent-aware systems that work the way you do.

2026 Summer AI/ML Engineer Intern

About the role

2026 Summer Research Engineer Intern

What You'll Build

Requirements

Sample Projects

About Dex

Other roles at Dex

Job details

Company

Funding

Founders

What happens next.

Confirm the fit

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