Senior Software Engineer

Mozilla

About The Position

The Firefox Monitor Engineering Team builds tools that help people understand and respond to data breaches. We notify users when their credentials appear in exposed datasets and empower them to take back control of their online privacy. We operate at scale, serving millions of users, and our work sits at the intersection of security, data privacy, and product engineering. As a Senior Software Engineer on the Firefox Monitor team, you will be a core contributor to a modern, cloud-native Node.js/TypeScript full-stack application. This role spans feature development, infrastructure ownership, and application support. You'll own backend systems and integrations that keep users informed and protected, help maintain and evolve the cloud infrastructure the application runs on, and play an active role in keeping the service reliable and healthy in production. You'll do this while collaborating closely with frontend, SRE, and product teams to deliver reliable, privacy-first features.

Requirements

7+ years of experience in software development with a strong focus on backend technologies
Deep expertise in Node.js and TypeScript, with experience building and leading backend engineering projects
Proficiency with PostgreSQL and SQL query optimization; experience with query builders such as Knex is a plus
Experience deploying and operating applications on GCP (Cloud Run, Pub/Sub, Cloud Logging) with a solid understanding of DevOps and SRE collaboration
Experience with AWS (S3) or similar cloud storage services
Hands-on experience with observability tooling including OpenTelemetry, Sentry, Prometheus, and Grafana
Familiarity with Redis for caching and session management
Experience with Next.js, React, and SCSS, with a willingness to contribute to full-stack development when needed
Experience with modern testing practices including unit testing (Vitest), end-to-end testing (Playwright), and component testing
Strong communication skills and ability to collaborate across engineering, product, and operations teams
Experience mentoring junior engineers and driving technical excellence in code quality, testing, and process improvements

Nice To Haves

Stripe or payment platform integrations
Mozilla Fluent or other i18n/l10n frameworks
Storybook for component-driven development
Performance/load testing
Data breach intelligence or cybersecurity domain knowledge

Responsibilities

Lead backend development in Node.js and TypeScript, building and maintaining server-side logic within a Next.js full-stack architecture
Design, implement, and maintain integrations with external data sources such as Have I Been Pwned (HIBP) and other breach intelligence providers, with a focus on data privacy and security
Build and maintain event-driven systems using Google Cloud Pub/Sub, and own cloud infrastructure on GCP ( GKE) and AWS (S3, SES)
Own and evolve the data layer, including PostgreSQL schema design and query optimization using Knex, and Redis caching strategies
Work closely with our SRE team to maintain and improve production environments, including monitoring and alerting with OpenTelemetry, Sentry, Prometheus, and Grafana
Triage and resolve production issues, partnering with SRE and support teams to investigate incidents, address bug reports, and keep the application running reliably
Periodically rotate into a Base Load Engineer (BLE) role, handling releases, dependency updates, and incoming work requests from customer support and other stakeholders
Partner with and support the frontend team in their work with React, TypeScript, Next.js, and SCSS, ensuring backend systems, APIs, and data contracts meet their needs
Partner with cross-functional teams to align on project goals, ensure seamless frontend-backend integration, and contribute to API design and evaluations
Participate in code reviews to maintain high standards of code quality and system reliability
Participate in security and privacy reviews, ensuring all data protection measures meet compliance standards

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)