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 • NetherlandsSenior💰 €66,000 - €88,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in building and maintaining production applications with Python/Django, while ensuring reliability and safe delivery through CI/CD practices and observability. Strong technical writing skills and a commitment to mentoring peers in operational excellence are essential.

Highest-signal resume keywords

Python/Django Application DevelopmentCI/CD Pipeline ManagementObservability and MonitoringTechnical Writing and DocumentationCollaboration in Distributed Teams

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Production Application DevelopmentAutomated Testing WorkflowsInfrastructure as CodeDebugging Complex Production IssuesCode Review StandardsIncident Response PracticesMetrics and LoggingService-Level ObjectivesAsynchronous Job TracingDeployment Workflows

Soft Skills

CollaborationCommunicationMentoringKnowledge SharingFeedback Provision

Tools & Technologies

Google CloudKubernetesChaos EngineeringDisaster Recovery TestingInternal Developer Platforms

Industry Keywords

Production ReadinessTrust and Safety SystemsOpen-Source ContributionsOperational ReadinessPolicy as Code

Tech Stack

Tools & technologies

CloudDjangoKubernetesPython

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 for safely developing, deploying, observing, and operating production services
Improve CI/CD pipelines using declarative, pipeline-as-code approaches
Deliver work iteratively through visible backlogs, feedback cycles, retrospectives, and stakeholder demonstrations
Write technical documentation, 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
Contribute through pull requests, code reviews, and discussions
Work on submission flows, trust and safety signals, DevHub and Reviewer tools modernization, 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 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 in operational and reliability practices
Commitment to Mozilla’s values: welcoming differences, being relationship-minded, practicing responsible participation, and having grit
Bonus: Google Cloud, Kubernetes, infrastructure-as-code, policy-as-code, SLOs, error budgets, chaos engineering, disaster recovery testing, production readiness reviews, trust and safety systems, or open-source contributions

Benefits

Comp & perks

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)