Senior Software Engineer Job at Mozilla

Senior Software Engineer

Mozilla

Location:

Category:
IT - Software Development

Contract Type:
Not provided

Salary:

Not provided

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Job Description:

addons.mozilla.org (AMO) is the foundation of the Firefox add-ons ecosystem. It’s a showcase for developers to publish and grow their extensions, and a place of discovery for millions of users who customize Firefox to make it their own. AMO carries the responsibility of building a great, secure, and trustworthy experience for both users and developers. As a Senior Software Engineer, you’ll bring a passion for crafting beautiful, accessible experiences to AMO. You’ll work closely with designers and product managers to turn ideas into polished features, modernize the platform and its architecture, and see your work reach millions of people around the world.The Add-ons Engineering team builds and maintains AMO as a critical part of Firefox’s customizability.

Job Responsibility:

Design, build, and refine frontend experiences in AMO and DevHub, ensuring they are fast, accessible, and user-friendly
Contribute to modernization and improvements in architecture and maintainability
Help keep the platform safe and trustworthy, with attention to security and user trust
Step in to resolve issues impacting users and developers, from small bugs to larger incidents
Collaborate with designers, product managers, QA, and community contributors to deliver end-to-end improvements
Contribute in the open through pull requests, code reviews, and discussions

Requirements:

4+ years of professional experience building modern web applications
Proficiency in React, JavaScript/TypeScript, HTML, and CSS, with strong debugging and testing skills
Familiarity with Python/Django or similar backend frameworks
Understanding of web security principles and practices
Awareness of accessibility, responsive design, and API integration
Strong collaboration and communication skills in a distributed team environment
Comfortable working in an environment that includes contributions from both staff and the open-source community
Commitment to our values: Welcoming differences, Being relationship-minded, Practicing responsible participation, Having grit

Nice to have:

Experience with relational databases such as MySQL
Exposure to cloud infrastructure (Google Cloud or similar)
Contributions to open source projects
Other front end stacks such as Jinja2
Experience mentoring or supporting junior developers

What we offer:

Generous performance-based bonus plans
Rich medical, dental, and vision coverage
Generous retirement contributions with 100% immediate vesting
Quarterly all-company wellness days
Country specific holidays plus a day off for your birthday
One-time home office stipend
Annual professional development budget
Quarterly well-being stipend
Considerable paid parental leave
Employee referral bonus program
Other benefits (life/AD&D, disability, EAP, etc. - varies by country)
Flexible work environment
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)
Reimbursement for professional development (up to $3,000/year)
A work setup including the latest hardware and software of your choice

Additional Information:

Job Posted:
January 02, 2026

Work Type:

Remote work

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