Senior Security Engineer, Add-ons Operations

• Build resilient systems that power the Firefox add-ons ecosystem at addons.mozilla.org (AMO), accelerating the review and operations team to deliver a first-class experience for extension developers and millions of Firefox users. • Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and the DevHub. • Work full stack across React/TypeScript frontends, Django backend, and MySQL on Google Cloud, contributing to platform reliability through deployments, monitoring, and incident response. • Help keep the ecosystem safe and trustworthy through abuse report management, policy compliance, and trust and safety signals. • Work fully remotely from the UK, Germany, France, or Canada.

• Bring proven experience building modern web applications. • Bring strong experience with Python/Django or a comparable backend framework. • Bring a solid understanding of web security principles and practices. • Bring strong collaboration and communication skills within a distributed team environment. • Show the ability to navigate ambiguity, explore solutions, and shape direction in new problem spaces.

• Bring experience building automated security or moderation systems. • Bring exposure to cloud infrastructure, particularly Google Cloud. • Bring a history of contributions to open source projects. • Bring experience with policy-compliant ecosystem moderation tools.

• Deliver major features and architectural improvements across automated moderation pipelines, Reviewer tools, and the DevHub. • Build robust observability systems and data-backed insights that help the team understand platform health and user trust signals. • Improve platform reliability through proactive monitoring, deployments, and incident response on Google Cloud. • Step in to resolve issues impacting users and developers, from small bugs through to larger incidents. • Contribute in the open through pull requests, code reviews, and community discussions, collaborating with designers, product managers, QA, and external contributors.

• Receive generous performance-based bonus plans shared across the team. • Access rich medical, dental, and vision coverage, plus generous retirement contributions with 100% immediate vesting. • Take considerable paid parental leave and a day off for your birthday, plus quarterly all-company wellness days. • Receive a one-time home office stipend, an annual professional development budget, and a quarterly wellbeing stipend. • Benefit from an employee referral bonus programme and additional benefits including life, AD&D, disability, and EAP cover.

Mozilla Corporation is the non-profit-backed technology company behind Firefox, used by more than 225 million people monthly. Wholly owned by the Mozilla Foundation, Mozilla builds open-source software that enables people to enjoy the internet on their own terms — never beholden to shareholders, always focused on making the internet better for people.