Senior Software Engineer, Add-Ons

This is a fully remote position, open to applicants in United Kingdom.

📋 Description

• Implement significant features and architectural enhancements across the Add-ons stack, including automated moderation frameworks, Reviewer tools, and DevHub.

• Set and uphold engineering standards for code evaluations, production readiness, runbooks, incident management, on-call practices, coding conventions, and infrastructure as code.

• Develop comprehensive observability systems and data-driven insights.

• Provide constructive peer feedback, share expertise, and assist in the professional growth of colleagues.

• Create and refine systems that support safe development, deployment, monitoring, and operation of production services.

• Enhance CI/CD pipelines using declarative, pipeline-as-code methodologies.

• Deliver work in an iterative manner through transparent backlogs, brief feedback loops, retrospectives, and stakeholder presentations.

• Produce technical documentation, including design notes, Architecture Decision Records, runbooks, and incident reports.

• Trace requests and asynchronous tasks across unfamiliar codebases to diagnose failures and propose enhancements.

• Collaborate with designers, product managers, QA, and community contributors to drive end-to-end improvements.

• Contribute through pull requests, code reviews, and collaborative discussions.

• Develop features such as submission flows, trust and safety signals, and modernization of DevHub and Reviewer tools.

• Work with technologies including Python/Django, MySQL, React/TypeScript, and asynchronous processing systems.

• Create internal developer platforms and paved paths for secure, consistent software delivery.

• Participate in team ceremonies and contribute to process enhancements.

• Assist with deployments, monitoring, and incident response to ensure platform reliability.

⛳️ Requirements

• Extensive hands-on experience in building and maintaining production applications using Python/Django.

• Proven experience in operating and enhancing production software systems with a focus on reliability and safe delivery.

• Strong background in CI/CD systems and managing pipelines and infrastructure declaratively as code.

• Proficiency in designing or refining automated testing and deployment workflows, including integration testing and staged or progressive delivery.

• Solid understanding of observability principles, including metrics, logging, tracing, service-level objectives, and actionable alerting.

• Experience in building or maintaining internal tools or platforms utilized by other engineering teams.

• Experience in defining or enhancing engineering practices such as code review standards, operational readiness, runbooks, incident response, on-call expectations, or definitions of done.

• Ability to comprehend and navigate unfamiliar codebases while tracing application behavior across frontend, backend, asynchronous tasks, data storage, and infrastructure.

• Experience in diagnosing complex production issues and translating findings into lasting system improvements.

• Strong technical writing capabilities, including design documents, ADRs, runbooks, and incident reports.

• Experience working iteratively with a visible backlog, regular stakeholder feedback, and retrospectives.

• Excellent collaboration and communication skills in a distributed team setting.

• Willingness to share knowledge and mentor peers in operational and reliability best practices.

• Commitment to Mozilla values: embracing diversity, fostering relationships, engaging in responsible participation, and demonstrating perseverance.

• Bonus: Familiarity with Google Cloud, Kubernetes, infrastructure-as-code, policy-as-code, SLOs, error-budget reliability practices, chaos engineering, disaster recovery testing, production readiness evaluations, trust and safety systems, automated moderation, abuse prevention, and contributions to open-source projects.

🏝️ Benefits

• Competitive performance-based bonus plans for all eligible employees - we celebrate our successes as one unified team.

• Comprehensive medical, dental, and vision benefits.

• Generous retirement contributions with 100% immediate vesting (regardless of personal contributions).

• Quarterly company-wide wellness days where everyone takes a collective pause.

• Country-specific holidays along with an additional day off for your birthday.

• One-time stipend for setting up a home office.

• Annual budget for professional development.

• Quarterly well-being stipend.

• Extensive paid parental leave.

• Employee referral bonus program.

• Additional benefits (including life/AD&D, disability, EAP, etc. - varies by country).