Overview

As a Senior Software Engineer on the AMO/DevHub domain, you will help shape the Firefox add-ons ecosystem by delivering major features and architectural improvements. You'll partner with engineers, reviewers, product leads, and the community to modernize the platform, improve reliability, and scale review and moderation. You'll build observable, data-driven systems and guide the team with strong engineering practices.

This role offers impact at scale and a chance to contribute to an open, privacy-respecting internet.

Compensaciones / Incentivos generous performance-based bonus medical, dental, and vision coverage retirement contributions with immediate vesting well-being stipend and wellness days home office stipend professional development budget

Responsabilidades

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

Establish and maintain engineering standards (code review, production readiness, incident response, runbooks, IaC)

Create robust observability systems and data-backed insights

Mentor peers and share knowledge to grow the team

Improve CI/CD pipelines with declarative, pipeline-as-code approaches

Deliver work iteratively with clear backlog and stakeholder reviews

Produce technical documentation (design notes, ADRs, runbooks, incident reports)

Trace and diagnose failures across frontend, backend, asynchronous jobs, data stores, and infra

Collaborate with designers, PMs, QA,



and community contributors to ship end-to-end improvements

Contribute to open source via PRs, code reviews, and discussions

Work on: feature development (submission flows, trust signals, DevHub/Reviewer tools modernization)

AMO stack: Python/Django, MySQL, React/TypeScript, asynchronous processing

Internal developer platforms: build tools to help teams ship and operate safely

Requisitos principales Hands-on production-grade Python/Django experience

Proven reliability-focused production software operations

Strong CI/CD experience and declarative infrastructure

Experience designing automated tests and progressive delivery

Strong observability knowledge (metrics, logging, tracing, SLOs, alerting)

Experience building internal tools/platforms used by engineers

Defining/improving engineering practices (code review, runbooks, incident response)

Ability to read unfamiliar codebases and trace end-to-end behavior

Proven debugging of complex production issues and turning learnings into improvements

Strong technical writing (design docs, ADRs, runbooks, incident reports)

Experience working with a visible backlog and stakeholder feedback

Strong collaboration and communication in distributed teams

Willingness to mentor peers on reliability practices

Commitment to Mozilla values: welcoming differences, relationship-minded, responsible participation, grit collaboration communication mentorship

Python/Django

MySQL

React/TypeScript

📌 Senior Software Engineer, Add-Ons (Tarragona)
🏢 Mozilla
📍 Tarragona