Senior Software Engineer, WebExtensions

About the Role

The WebExtensions team is a critical part of Mozilla's mission to make the internet better for people. As a member of this team, you will collaborate with experts across Mozilla and help advance cross-browser compatibility and the path toward standardization. Your work will keep extensions safe, powerful, and reliable for developers and millions of Firefox users.

Mozilla Corporation is a non-profit-backed technology company that has shaped the internet for the better over the last 25 years. With more than 225 million people around the world using Mozilla products each month, the company is shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies.

What You Will Do

• Implement and maintain WebExtensions APIs and Addon Management, balancing power, safety, and performance, as well as user interfaces in Firefox.
• Debug and fix issues affecting extensions in Firefox.
• Collaborate with product managers, QA, and the AMO engineering team to deliver features end-to-end.
• Contribute to Mozilla-owned extensions and system add-ons.
• Participate in open source workflows: code reviews, pull requests, and discussions in Bugzilla/GitHub.
• Support extension developers by helping diagnose issues and improving tooling/documentation.
• Work closely with the engineering team to identify and prioritize project requirements.
• Develop and maintain technical documentation for WebExtensions APIs and Addon Management.
• Collaborate with the security team to ensure the security and integrity of WebExtensions and Addon Management.

What We Are Looking For

• 4+ years of professional experience in software development.
• Strong proficiency in JavaScript, DOM APIs, HTML, and CSS.
• Experience working with open-source software and collaborating with distributed teams.
• Strong understanding of web browser architecture and extensions ecosystems.
• Excellent problem-solving skills and attention to detail.
• Ability to work in a fast-paced environment and prioritize multiple tasks.
• Experience with agile development methodologies and version control systems.
• Strong communication and collaboration skills.

Nice to Have

• Experience working with Gecko or other browser engines.
• Familiarity with Mozilla's open-source ecosystem and community.
• Experience with cloud-based technologies and DevOps practices.
• Knowledge of security best practices and secure coding techniques.

Benefits and Perks

• Opportunity to work on a high-impact project that shapes the future of the internet.
• Collaborative and dynamic work environment with a team of experts.
• Flexible working hours and remote work options.
• Comprehensive benefits package, including health insurance and retirement plan.
• Professional development opportunities, including training and conference attendance.
• Access to the latest technologies and tools.
• Chance to work on open-source software and contribute to the Mozilla community.

• Make sure to highlight your experience working with open-source software and collaborating with distributed teams in your application.
• Familiarize yourself with Mozilla's open-source ecosystem and community to demonstrate your enthusiasm for the company's mission.
• Be prepared to discuss your problem-solving skills and attention to detail, as well as your experience working in a fast-paced environment.
• Showcase your proficiency in JavaScript, DOM APIs, HTML, and CSS, and be prepared to provide examples of your work.
• Research the company's culture and values to demonstrate your understanding of Mozilla's unique approach to technology and community engagement.
• Prepare to discuss your experience with agile development methodologies and version control systems, and be ready to provide examples of your experience working in a collaborative environment.