Senior Software Engineer, Add-Ons

Mozilla

. Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and DevHub .

Posted 9/15/2026full-timeRemote • FinlandSenior💰 €45,000 - €60,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in building and maintaining production applications with Python/Django, improving CI/CD pipelines, and establishing engineering standards for operational readiness. Strong capabilities in observability, technical writing, and collaborative practices in a distributed team environment are essential.

Highest-signal resume keywords

Python/Django Application DevelopmentCI/CD Pipeline ImprovementObservability and MonitoringTechnical WritingEngineering Standards and Practices

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Hard Skills

Production Application DevelopmentAutomated Testing WorkflowsInfrastructure as CodeDebugging Complex Production IssuesCode Review StandardsIntegration TestingMetrics and LoggingAsynchronous Job TracingIncident ResponseRunbook Creation

Soft Skills

CollaborationCommunicationMentoringKnowledge SharingFeedback Provision

Tools & Technologies

DevHubReviewer ToolsAutomated Moderation PipelinesInternal Developer PlatformsVisible Backlogs

Industry Keywords

Production ReadinessOperational ExcellenceStakeholder EngagementIterative DevelopmentMozilla Values

Tech Stack

Tools & technologies

DjangoPython

About the role

Key responsibilities & impact

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 using 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 end-to-end in unfamiliar codebases to understand failures and identify improvements
Collaborate with designers, product managers, QA, and community contributors
Contribute through pull requests, code reviews, and discussions
Work on submission flows, trust and safety signals, DevHub and Reviewer tools modernization, AMO application systems, internal developer platforms, team process, engineering standards, deployments, monitoring, and incident response

Requirements

What you’ll need

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 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, stakeholder feedback, and retrospectives
Strong collaboration and communication skills in a distributed team environment
Willingness to share knowledge and mentor peers
Commitment to Mozilla values: welcoming differences, being relationship-minded, practicing responsible participation, and having grit

Benefits

Comp & perks

Generous performance-based bonus plans to all eligible employees
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)