Senior Security Engineer, -ons Ops — Remote

Team:
Firefox Locations:
Remote Germany, Remote UK, Remote France, Remote Canada

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Why Mozilla?

About this team and role:

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. Behind the scenes are the Dev Hub which enables developers to manage their extensions. To manage the ecosystem there are a series of Reviewer tools and automated moderation systems.

As a Senior Software Engineer - Operations, you’ll bring a passion for crafting resilient systems that accelerate our review and operations team to provide a first-class experience for Add-on developers. You’ll work closely with engineers, reviewers, developer relations, and Add-ons leadership to turn ideas into polished features, modernize the platform and its architecture, and see your work reach millions of people around the world.

What you’ll do:

• Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and Dev Hub.
• Create robust observability systems and data-backed insights.
• Provide peer feedback, share knowledge and help others grow.
• Improve platform reliability through deployments, monitoring, and incident response.
• 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.
• Work on:
• Full stack development: React/Type Script frontends, Django backend, MySQL datastore.
• Platform reliability: deployments, monitoring, and incident response on Google Cloud.
• Feature development: submission flows, trust and safety signals, Dev Hub and Reviewer tools modernization.
• Ecosystem moderation : abuse report management, policy compliance, and ecosystem safety.
• Open collaboration: We work in the open, with contributions from Mozilla staff and community members.

What you’ll bring:

• Experience building modern web applications.
• Strong experience with Python/Django or similar backend frameworks.
• Understanding of web security principles and practices.
• Strong collaboration and communication skills in a distributed team environment.
• Adept at navigating ambiguity, exploring solutions, and shaping direction in new problem spaces.
• Commitment to our values:
• Being relationship-minded
• Having grit
• Experience in building automated security systems.
• Exposure to cloud infrastructure (Google Cloud or similar).
• Contributions to open source projects.
• Experience with policy-compliant ecosystem moderation tools.

What you’ll get:

• Generous performance-based bonus plans to all eligible employees - we share in our success as one team
• Rich medical, dental, and vision coverage
• Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute)
• Quarterly all-company wellness days where everyone takes a pause together
• Country specific holidays plus a day off for your birthday
• One-time home office stipend
• Quarterly well-being stipend
• Considerable paid parental leave
• Employee referral bonus program
• Other benefits (life/AD&D, disability, EAP, etc.
  
  - varies by country)

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…