Senior Staff AI & Agentic Systems Engineer

Why Mozilla?

Mozilla Corporation is the non-profit-backed technology company that has shaped the internet for the better over the last 25 years. We make pioneering brands like Firefox, the privacy-minded web browser. Now, with more than 225 million people around the world using our products each

month, we’re shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies. Our work focuses on diverse areas including AI, social media, security and more. And we’re doing this while never losing our focus on our core mission – to make the internet better for people.

The Mozilla Corporation is wholly owned by the non-profit 501© Mozilla Foundation. This means we aren’t beholden to any shareholders — only to our mission. Along with thousands of volunteer contributors and collaborators all over the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms.

About This Team and Role:

Mozilla is building a new browser infrastructure platform for the new generation of web automation. We are looking for an experienced Staff Engineer to join our early-stage team at Mozilla to lead the architectural design and implementation of our next-generation AI agent frameworks and workflows. This is a “ground-up” role within a fast-moving, nimble team, making it a perfect fit for someone with early-stage startup experience who thrives on a blank slate. You will be the technical anchor for our AI engineering efforts, establishing the patterns for how we build, evaluate, and scale autonomous capabilities.

This role sits within Mozilla’s New Products organization, which operates as an internal incubator for high-potential ventures. You will join a fast-paced autonomous team building a new product from its earliest stages.

What You’ll Do:

• Architect Agentic Systems from Zero: Design and deploy production-grade multi-agent frameworks, complex orchestration layers, and custom AI developer tooling.
• Balance Speed and Scale: Navigate the tension between rapid prototyping and long-term sustainability, knowing exactly when to cut corners to validate a concept and when to slow down to lay rock-solid architectural foundations.
• Orchestrate LLM Workflows: Navigate and integrate various commercial and open-source large language models, selecting and optimizing the right models for specific agentic behaviors.
• Accelerate with AI Tooling: Lead by example by extensively leveraging advanced AI coding tools to maximize velocity, while establishing best practices for AI-assisted engineering across the team.
• Drive Evaluation and Performance: Implement rigorous frameworks for benchmarking, prompt engineering, and evaluating agent reliability, latency, and accuracy.
• Collaborative Technical Leadership: Set engineering standards for code quality and system performance, mentoring other engineers and acting as a primary bridge between research and product.

What You’ll Bring:

• Deep Experience: You have 7+ years of professional software engineering experience, particularly in fast-paced environments where you’ve shipped complex systems from scratch.
• Pragmatic Architecture: A proven ability to judge technical debt. You know how to ship an MVP in days, but you also know how to design a clean API boundary so that early speed doesn’t block future scale.
• Agentic Mastery: You bring 2+ years of direct, hands-on production experience specifically building autonomous workflows, custom tools, and agentic systems.
• LLM Fluency: Deep familiarit…