[Remote] 0->1 Engineer, Open Source AI

Note: The job is a remote job and is open to candidates in USA. Mozilla is building a position in open source AI through research, community, tooling, and public advocacy. They are seeking an engineer to ship fast, working code and demos on top of Harbor and open source AI tooling, focusing on making layer architecture legible and engaging with the standards process.

Responsibilities

• Ship working tools, demos, and reference implementations on top of Harbor and open source AI tooling — fast. Days, not weeks. Code that makes architectural choices concrete enough for another developer to install, read, fork, and build on
• Make the layer architecture legible — reference implementations clean enough to read, documentation that maps the repo structure and clarifies the relationship between Web Agents API and Harbor SDK. If a developer or their coding assistant keeps reaching for the wrong primitive, that's yours to fix
• Be the technical practitioner in the room when it matters — a WICG call, a hackathon, a GitHub thread where a hard architecture question comes up. A community manager handles distribution and presence; your job is to show up with working code and real opinions when the conversation turns technical, and come back with a clear read on what developers are missing or getting wrong
• Use coding agents and AI-assisted development tools as the way you work, not a novelty. The repo already has a Cursor agent as a contributor
• Engage with the standards process — WICG, W3C — as a practitioner
• Fix the real technical gaps. Real problems on the table right now: proper function calling in the bridge (currently using response parsing), permission granularity beyond origin-level, streaming abort, WASM MCP server tooling, Safari support. The shape of the work is this specific, but evolving
• As Mozilla's broader prototyping surface expands, identify and ship into adjacent opportunities where working code can move a conversation forward

Skills

• Strong software engineering fundamentals. You write code others can read — clear structure, obvious intent, reusable patterns. You know the difference between prototype-quality and production-quality and make that call deliberately
• Hands-on experience with the open source AI stack — inference, orchestration, agent frameworks, evaluation. You've built something real on top of open models, and you have opinions about where current frameworks get the abstraction wrong
• Security instincts around agentic systems. You understand prompt injection as an architectural problem. You have a view on typed-verb surfaces vs. DOM-driving agents
• You can explain layered architectures to developers who don't share your context — in code, in docs, and in writing — clearly enough that developers and their AI assistants route to the right layer without guessing
• Strong written communication and credibility in public as a practitioner. You can explain what you built, why you shaped it the way you did, and what's still unresolved
• Fluency in Python and/or TypeScript, with enough range to pick up whatever the project needs
• Firefox and Chrome extension development. WebExtensions API, content scripts, background workers, message passing, native messaging — you've shipped something here
• MCP fluency. You've authored MCP servers — JS and ideally WASM — and designed tool schemas. OAuth integration for MCP servers is directly relevant. You understand what makes a tool surface good and where the current protocol has edges
• Local inference experience. Ollama, llama.cpp, MLX — you've run models on-device and understand what that imposes on API design
• Permission and capability system design is a real plus — scoped access, revocable grants, per-origin controls, OCAP patterns, information-flow controls, capability tokens
• Browser standards familiarity — WICG, W3C, explainer authorship — is a plus

Benefits

• Flexible hours and outcome-oriented working style

Company Overview