Staff Software Engineer - Networking

Mozilla (View all Jobs)


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Interview Process

1. Deep-dive discussions on technical and mentorship problems solved in the past. No live coding. Total of 3 rounds.

Programming Languages Mentioned


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The Role

The Mozilla Corporation's Gecko networking team is looking for skilled developers to work on a first-class networking stack and improve web experiences for millions of Firefox users. The team is working on the core of the browser that moves the web. The fundamental network protocols and features like HTTP, QUIC, caching and DNS are our responsibility. We strive to provide a performant and secure browsing experience for the users. Furthermore we work on advanced web platform networking API like Fetch and WebTransport. We improve our existing implementations and together with the broader community we advance the web through the evolution of relevant standards. 

Is debugging networking protocols or multi-threaded applications  an exciting challenge for  you? If you’re also enthusiastic about working collaboratively with a worldwide community, we'd love to hear from you!

Opportunities to collaborate with other browser teams, and working in the open is the norm. Firefox is a mature project always looking for new optimizations, and we are trying to write some of our new components in Rust. You’ll be responsible for writing code, tests, specifications, building prototypes, solving problems, and analyzing data. You'll get feedback from real users and synthesize it into bug reports, feature designs, and strategic direction to make the web platform even better over time.

In this role you will:

  • Improve Firefox’s web browsing experience with a particular focus on the networking stack and network related API, e.g. Fetch, WebTransport, etc.

  • Design and implement new web platform features in collaboration with the web community.

  • Debug and fix problems in our multi-threaded codebase.

  • Debug platform-specific networking issues.

  • Improve Firefox’s stability and correctness.

  • Analyze and reduce Firefox’s memory usage.

  • Work cooperatively with other Mozillians to identify and correct issues.

Your professional profile:

  • Proficient with C++.

  • Experience or interest in learning Rust.

  • Networking experience, including strong familiarity with tools such as Wireshark and protocols such as TCP, UDP, SSL/TLS, and HTTP.

  • Experience working on a cross-platform native application.

  • Creative problem-solver and skilled debugger.

  • Experience writing and debugging multi-threaded code.

  • Ability to learn a large and complex multi-language code base.

  • Excellent written and verbal communication skills.

  • Familiarity or interest in learning the modern web platform.

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 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


Req ID: R2020

Please mention No Whiteboard if you apply!
I'm a one-man team looking to improve tech interviews, and could use any support! 😄

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