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# Software Engineer

- **Company:** Mozilla Corporation
- **Location:** Madrid, Spain (Remote available)
- **Contract:** Permanent contract
- **Skills:** Microsoft Windows, Application Programming Interfaces (APIs), Apple Mac Systems, C++ (Programming Language), Code Review, Computer Programming, Linux, Firefox, Windows API, Open Source Technology, Data Analytics
- **Published:** September 1, 2026
- **Apply:** https://www.adzuna.es/contact-us.html

## About the Role

We contribute to the code driving the Firefox browser on a number of desktop platforms.About the role: A Senior Software Engineer contributes to architectural discussions, and driving feature development within a team.
At Mozilla, Senior Engineers are expected to work independently on scoped projects, collaborate closely with peers, and play a key role in delivering high-quality software that aligns with team goals.What you'll do:Contribute to the development and improvement of Firefox features related to installs, updates, and OS integrations.Help implement enhancements to the Firefox installation and update experience, using data insights to guide development.Tackle platform-specific challenges in low-level operating system integration on Windows and/or macOS.Collaborate with your manager and teammates to scope and prioritize work in alignment with the team's goals.Participate in code reviews and contribute to technical discussions with peers.Take ownership of complex bugs and lead efforts to improve the Firefox experience for hundreds of millions of users.Work closely with your geographically distributed team in a highly collaborative environment.What you'll bring: 3-5 years
experience as Software Engineer Experience with systems-level programming on at least one major platform (Windows, macOS).
Solid programming skills in C/C++.
Effective communicator and collaborator, especially in distributed teams.Ability to break down technical work and make steady progress within project timelines.A collaborative mindset and a desire to contribute to team success.Bonus PointsProgramming experience in Rust.Experience working with Windows and/or macOS APIs at a low level (e.g., Win32, Cocoa).
Additional experience with Linux, or macOS internals.Contributions to open source projects.We value a variety of voices within our team and at Mozilla.



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