Full-Stack Engineer

Cognition•San Francisco, CA

1d•$260,000 - $300,000

About The Position

Cognition is an applied AI lab building end-to-end software agents. We are behind Devin, the first AI software engineer, and Windsurf, an AI-native IDE. Our vision is AI that works alongside engineers as a genuine teammate, not a tool. We are a small, talent-dense team of competitive programmers, former founders, and researchers from Scale AI, Palantir, Cursor, Google DeepMind, and others. Full-Stack Engineers at Cognition own the product from end to end. You will build the backend systems that orchestrate agents, manage state across long-running tasks, and serve millions of requests reliably, as well as the frontend interfaces that make Devin and Windsurf feel fast, intuitive, and genuinely different from anything else a developer has used. This is not a role where front and back are siloed: the best work here happens when the engineer who understands the agent's execution model is the same one deciding how to surface it to the user. If you care deeply about both systems and craft, and want to work on products that are actively redefining how software gets built, this is the role.

Requirements

Strong backend engineering: Proficiency in Python; experience building reliable, well-structured APIs and services that operate at scale.
Strong frontend engineering: Proficiency in TypeScript and React; you build interfaces that are fast, accessible, and maintainable, with a high bar for UX quality.
Full-stack fluency: Comfort moving between layers without losing depth; you know when to optimize the query, when to fix the component, and how the two interact.
Product instinct: You care about how things feel to use and have shipped features that real users depend on.
Velocity without shortcuts: A track record of shipping quickly while maintaining code quality that a high-density team expects.
Curiosity about agents and AI: You have dug into how LLMs and agents work and think seriously about what it takes to make AI-powered products behave reliably.

Nice To Haves

Relevant industry experience: Prior experience at a frontier AI lab, applied AI company, or developer tools company; you know what good looks like in this category.
Degree from a top-tier university: BS, MS, or equivalent in Computer Science, Mathematics, Engineering, or a related technical discipline from a highly selective program.

Responsibilities

Build and own full-stack features: Take features from API design through backend logic to polished UI, with full ownership over quality and delivery at every layer.
Develop agent-facing backend systems: Build the APIs, services, and data pipelines that power Devin's task execution, session management, tool integrations, and real-time event streams.
Craft the frontend experience: Build the interfaces developers interact with daily inside Devin and Windsurf; fast, responsive, and designed to make complex agent behavior feel approachable.
Integrate model capabilities into the product: Work with researchers and infra engineers to bring new model features to users, bridging the gap between what the model can do and what the product exposes.
Raise the bar on performance and reliability: Own the quality of what you ship at both layers, from API latency and backend correctness to frontend responsiveness and UI consistency.