Senior Software Engineer – Remote, Open-Source Platform

Mozilla; Finland; Remote; EUR 45,000 - 60,000; Full time

Benefits offered by this job

Generous performance-based bonus plans

Rich medical, dental, and vision

Generous retirement contributions

Annual professional development budget

Remote-friendly culture

Job summary

Mozilla is seeking a Senior Software Engineer to help accelerate review and moderation for Add-ons, delivering major features and platform modernization at scale.

You will work with Python/Django, MySQL, React/TypeScript and build reliable production services while improving CI/CD pipelines and operational readiness. Join a distributed team delivering impact to millions of users globally.

Qualifications

• 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.

Responsibilities

• Deliver major features and architectural improvements across the Add-ons stack, including automated moderation pipelines, Reviewer tools, and DevHub.
• Help establish and maintain engineering standards across areas such as code review, definition of done, 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 the systems that enable Add-ons engineering to safely develop, deploy, observe, and operate production services.
• Improve our CI/CD pipelines using declarative, pipeline-as-code approaches that make changes reproducible, testable, and easy to review.
• Deliver work iteratively using a visible backlog, short feedback cycles, retrospectives, and demonstrations to stakeholders.
• Write clear technical documentation, including design notes, Architecture Decision Records, runbooks, and incident write-ups.
• Work effectively in unfamiliar codebases, tracing requests and asynchronous jobs end-to-end to understand failures and identify opportunities for improvement.
• Collaborate with designers, product managers, QA, and community contributors to deliver end-to-end improvements.
• Contribute in the open through pull requests, code reviews, and discussions.
• Work on: Feature development, AMO application systems (Python/Django, MySQL, React/TypeScript), Internal developer platforms, Team process, Engineering standards, Platform reliability.

Skills

Python/Django

CI/CD

Observability

Production debugging

Documentation

Distributed systems

React/TypeScript

Tools

Django

MySQL

React/TypeScript

Job description

Mozilla is seeking a Senior Software Engineer to help accelerate review and moderation for Add-ons, delivering major features and platform modernization at scale.

You will work with Python/Django, MySQL, React/TypeScript and build reliable production services while improving CI/CD pipelines and operational readiness. Join a distributed team delivering impact to millions of users globally.