Staff Software Engineer, DOM Workers Storage

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(c) 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:

Are you enthusiastic about optimizing software that millions of people rely on every day? Do you enjoy the challenge of debugging complex multi-threaded C++ code? Are you excited about web technologies and the applications built on them that enrich users’ lives? If so, we’d love to hear from you!

We are hiring a staff engineer for the DOM team, responsible for the Gecko implementation of web standards including IndexedDB, File System, Web Workers, Service Workers, Push API and Notifications API that powers websites people use via Firefox.

In this role, your first major challenge will be improving the reliability of storage initialization, across mobile and desktop platforms, where it impacts millions of Firefox users. Beyond that, you’ll play a key role in advancing Gecko and the Web platform: shaping web standards, implementing APIs, and collaborating across teams and browsers to deliver new capabilities that make the Web stronger for everyone. Your responsibilities will include writing code, tests, building prototypes and solving problems as well as contributing to the standards process , while continuously learning and growing as a technical leader.

What you’ll do:

• Improve Storage, Workers and system-level surfaces of our Web engine, with a strong focus on performance, stability and security
• Develop and debug in a large, complex, multi-threaded, and multi-process codebase
• Develop and debug across multiple platforms
• Investigate issues and propose solutions and architectural improvements
• Drive features and projects from start to completion
• Read and implement API specifications, and contribute to the standards process
• Collaborate with the widespread Firefox team on shared goals

What you’ll bring:

• Proficiency in C++
• Deep experience with multi-threaded, multi-process codebases, including work on performance-critical, sandboxed or storage architectures
• Ability to work with web specifications (like IndexedDB, File System, Web Workers, Service Workers), with the curiosity and adaptability to quickly deepen this expertise
• Cross-platform development experience with native applications (desktop and mobile)
• Proven ability to deliver maintainable solutions in large, evolving codebases
• Strong problem-solving skills, able to diagnose complex issues without clear logs or reliable reproduction steps
• Great written communication skills and ability to lead discussions effectively, both in writing and verbally
• Commitment to our values:
• Welcoming differences
• Being relationship-minded
• Practicing responsible participation
• Having grit

About Mozilla

Mozilla exists to build the Internet as a public resource accessible to all because we believe that open and free is better than closed and controlled. When you work at Mozilla, you give yourself a chance to make a difference in the lives of Web users everywhere. And you give us a chance to make a difference in your life every single day. Join us to work on the Web as the platform and help create more opportunity and innovation for everyone online.

Commitment to diversity, equity, inclusion, and belonging

Mozilla understands that valuing diverse creative practices and forms of knowledge are crucial to and enrich the company’s core mission. We encourage applications from everyone, including members of all equity-seeking communities, such as (but certainly not limited to) women, racialized and Indigenous persons, persons with disabilities, persons of all sexual orientations, gender identities, and expressions.

We will ensure that qualified individuals with disabilities are provided reasonable accommodations to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment, as appropriate. Please contact us at [email protected] to request accommodation.

We are an equal opportunity employer. We do not discriminate on the basis of race (including hairstyle and texture), religion (including religious grooming and dress practices), gender, gender identity, gender expression, color, national origin, pregnancy, ancestry, domestic partner status, disability, sexual orientation, age, genetic predisposition, medical condition, marital status, citizenship status, military or veteran status, or any other basis covered by applicable laws. Mozilla will not tolerate discrimination or harassment based on any of these characteristics or any other unlawful behavior, conduct, or purpose.

Group: C

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Req ID: R2932