Senior Software Engineer, Add-Ons

🕒 September 15

🇬🇧 United Kingdom – Remote

💵 £66k - £87k / year

⏰ Full Time

🟠 Senior

🧑‍💻 Full-stack Engineer

👻 Ghost score 0%

What it means: how likely this posting is sitting open without active hiring.How to read it: 60% or higher means we think this is a ghost. Lower scores are less of a worry.How we score it: age, reposts, open roles vs team size, how fast jobs close, and whether pay is listed.Fine print: an estimate from public data, not a judgment of the company. Real jobs can score high, so treat it as a hint, not a fact.

Apply Now

Find Similar Remote Jobs

Set Up Email Alert For New Jobs

📊 Check your resume score for this job

Improve your chances of getting an interview by checking your resume score before you apply.

Upload Resume

Mozilla

WebsiteLinkedInAll Job Openings

501 - 1000 employees

Founded 1998

👥 B2C

🔒 Cybersecurity

B2C • Cybersecurity • Software

Mozilla is a non-profit organization dedicated to promoting an open and accessible internet. They are the makers of the popular Firefox browser, which emphasizes user privacy, speed, and control. Mozilla also offers a range of products that focus on internet security and privacy, including Mozilla VPN, Firefox Relay, and Mozilla Monitor. Additionally, the organization is involved in open-source projects, AI innovation, and advocating for digital rights. Mozilla aims to empower users with trustworthy technology and policies that protect privacy, support open-source AI development, and foster accountability for tech companies.

📋 Description

• Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and DevHub • Establish and maintain engineering standards for code review, production readiness, runbooks, incident response, on-call practices, coding conventions, and infrastructure as code • Create robust observability systems and data-backed insights • Provide peer feedback, share knowledge, and help others grow • Build and improve systems that enable safe development, deployment, observation, and operation of production services • Improve CI/CD pipelines using declarative, pipeline-as-code approaches • Deliver work iteratively through visible backlogs, short feedback cycles, retrospectives, and stakeholder demonstrations • Write technical documentation, including design notes, Architecture Decision Records, runbooks, and incident write-ups • Trace requests and asynchronous jobs across unfamiliar codebases to understand failures and identify improvements • Collaborate with designers, product managers, QA, and community contributors on end-to-end improvements • Contribute through pull requests, code reviews, and discussions • Develop features such as submission flows, trust and safety signals, and DevHub and Reviewer tools modernization • Work with Python/Django, MySQL, React/TypeScript, and asynchronous processing systems • Create internal developer platforms and paved paths for safe, consistent software delivery • Contribute to team ceremonies and process improvement • Support deployments, monitoring, and incident response for platform reliability

🎯 Requirements

• Strong hands-on experience building and maintaining production applications with Python/Django • Experience operating and improving production software systems where reliability and safe delivery matter • Strong experience with CI/CD systems and treating pipelines and infrastructure declaratively as code • Experience designing or improving automated testing and deployment workflows, including integration testing and staged or progressive delivery • Strong understanding of observability, including metrics, logging, tracing, service-level objectives, and actionable alerting • Experience building or maintaining internal tools or platforms used by other engineering teams • Experience defining or improving engineering practices such as code review standards, operational readiness, runbooks, incident response, on-call expectations, or definitions of done • Ability to read and understand unfamiliar codebases and trace application behavior across frontend, backend, asynchronous jobs, data stores, and infrastructure • Experience debugging complex production issues and turning findings into lasting system improvements • Strong technical writing skills, including design documents, ADRs, runbooks, and incident reports • Experience working iteratively with a visible backlog, regular stakeholder feedback, and retrospectives • Strong collaboration and communication skills in a distributed team environment • Willingness to share knowledge and mentor peers in operational and reliability practices • Commitment to Mozilla values: welcoming differences, being relationship-minded, practicing responsible participation, and having grit • Bonus: Google Cloud, Kubernetes, infrastructure-as-code, policy-as-code, SLOs, error-budget reliability practices, chaos engineering, disaster recovery testing, production readiness reviews, trust and safety systems, automated moderation, abuse prevention, and open-source contributions

🏖️ Benefits

• 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 • 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)