Principal Engineer, Mozilla
New Products
Offers performance-based bonus plans
Designs, builds, and distributes internet software
Be an early applicant
Designs, builds, and distributes internet software
1001+ employees
Be an early applicant
Offers performance-based bonus plans
1001+ employees
Company mission
To make sure that the internet remains accessible, open, and transparent to everyone.
Role
Who you are
- If you thrive on rolling up your sleeves, love shipping code that developers adore, and enjoy shaping green-field products from the ground up, we’d love to meet you
- 10+ years of software engineering experience building high-performance developer tools, SDKs, or distributed systems, with at least 3 years leading technical teams or large projects
- Expert-level proficiency in at least two of: Go, Ruby (Rails), Python or TypeScript/JavaScript.
- Proven track record architecting and shipping complex, high-throughput systems in production environments (cloud, edge, or hybrid)
- Deep understanding of browser internals, automation frameworks (e.g., Playwright, Puppeteer, Selenium), and secure web interaction paradigms
- Hands-on experience and opinions about modern AI/ML workflows or agent frameworks such as LangChain, LlamaIndex, or custom in-house systems
- Strong focus on code quality, testability, performance, and operational excellence; familiarity with TDD, automated testing, and observability stacks
- Exceptional communication skills with the ability to collaborate across disciplines and levels, from junior engineers to executive leadership
Desirable
- Prior experience as a founding or early-stage CTO, Principal Engineer, or Staff+ engineer at a fast-growing startup or open-source project
- Experience building to production systems in browser automation, AI tooling, or developer infrastructure
- Knowledge of privacy-preserving technologies, secure computation, or web standards bodies
- Experience optimizing build systems, WebAssembly pipelines, or cross-language bindings
- Public speaking or writing history (talks, blogs, whitepapers) explaining complex technical topics to diverse audiences
What the job involves
- The New Products team at Mozilla is building a browser-automation stack for AI agents
- Our mission is to make it effortless for developers to integrate fast, reliable web interactions into their agentic applications
- We are seeking a founding Principal Software Engineer who will set the technical vision, architect the platform, and spend the majority of their time writing production code alongside the team
- You will guide a small, fast-moving group of engineers, and personally deliver the core libraries, services, and tooling that empower the next generation of intelligent web automation
- Technical Strategy & Architecture: Define and communicate the long-term technical roadmap for our browser-automation stack, balancing rapid iteration with long-term maintainability and scalability
- Hands-On Development: Write elegant, high-performance code daily in languages such as Go, Ruby on Rails, and TypeScript. Rapidly prototype, benchmark, and ship features to production
- System Design & Infrastructure: Design distributed, fault-tolerant services and developer-facing SDKs/APIs. Own cloud infrastructure, CI/CD pipelines, security, and observability
- Team Leadership & Mentorship: Grow, mentor, and inspire a world-class engineering team. Conduct thoughtful code reviews, establish the engineering culture, and foster a team of technical excellence and psychological safety
- Collaboration & Product Direction: Work closely with product, design, and developer-relations to ensure technical choices align with developer needs and business goals. Turn community feedback into concrete improvements
- Stakeholder Communication: Translate complex technical trade-offs into clear language for executives, partners, and cross-functional teams. Provide regular updates on progress, risks, and mitigation strategies
Our take
Mozilla creates and manages a range of free-to-use software products. Their most well-known product is Firefox, the fourth most popular internet browser in the world. Mozilla is a not-for-profit with a focus on promoting online privacy. The company has a published manifesto outlining its commitment to keeping a balance between commercial profit and public benefit.
The companies other products include Bugzilla, a bug management platform, and Pocket, an award-winning digital content filing service. In direct odds with Google, Mozilla has recently launched a new product Mozilla VPN. The VPN or virtual private network enables users to browse the internet without being tracked. Companies such as Google rely on tracking user behavior online to target them with advertising.
Mozilla was also instrumental in creating the programming language Rust, which is admired for its brevity. Rust uses roughly half the amount of code as C++ to produce the same results.
Freddie
Company Specialist at Welcome to the Jungle
Insights
12% employee growth in 12 months
Company
Funding (last 2 of 3 rounds)
Apr 2018
$1.2m
GRANT
Jan 2005
$0.3m
ANGEL
Total funding: $3.5m
Company benefits
- Health, Dental, and Vision Insurance
- Life Insurance + Accidental Death & Dismemberment
- Short-Term Disability and Long-Term Disability Insurance
- Employee Assistance Program (EAP)
- Retirement Plan contributions
- 20 Paid Time Off days per year (prorated) + your birthday
- Company Holidays + Shutdown
- Wellness budget
- Reimbursement for professional development (up to $3,000/year)
- Industry-leading paid parental leave (up to 26 weeks of fully paid leave for childbearing parents and up to 12 weeks for non-childbearing parents)
- Flexible work environment (nearly half of Mozillians work remotely)
- A work setup including the latest hardware and software of your choice
Company HQ
Rincon Hill, San Francisco, CA
Leadership
Mitchell Baker
(CEO & Chairwoman)Mitchell worked as a lawyer and at Netscape Communications before co-founding Mozilla in 2003. They have served as Chairwoman of Mozilla Foundation since then, and CEO as of April 2020.
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