Senior Software Engineer

About the Team and Role

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 collaborate closely with frontend, SRE, and product teams to deliver reliable, privacy‑first features.

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, focusing 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 the 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.
• Collaborate 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.

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 Kubernetes.
• Experience with GCP (Pub/Sub, Cloud Logging) and a solid understanding of DevOps and SRE collaboration.
• Experience with Infrastructure as Code tools such as Terraform.
• 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.

Bonus Points

• 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.

Benefits

• Generous performance‑based bonus plans for 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.
• Additional benefits (life/AD&D, disability, EAP, etc., varying by country).

About Mozilla

Mozilla exists to build the Internet as a public resource accessible to all because we believe that open and free is better than closed and controlled. When you work at Mozilla, you give yourself a chance to make a difference in the lives of Web users everywhere, and we give you a chance to make a difference in your life every single day. Join us to work on the Web as the platform and help create more opportunity and innovation for everyone online.

Commitment to Diversity, Equity, Inclusion, and Belonging

Mozilla values diverse creative practices and forms of knowledge as crucial to and enriching to the company’s core mission. We encourage applications from everyone, including members of all equity‑seeking communities, such as (but certainly not limited to) women, racialized and Indigenous persons, persons with disabilities, persons of all sexual orientations, gender identities, and expressions.

We will ensure that qualified individuals with disabilities are provided reasonable accommodations to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment, as appropriate. Please contact us at hiringaccommodation@mozilla.com to request accommodation.

We are an equal‑opportunity employer and do not discriminate on the basis of race (including hairstyle and texture), religion (including religious grooming and dress practices), gender, gender identity, gender expression, color, national origin, pregnancy, ancestry, domestic partner status, disability, sexual orientation, age, genetic predisposition, medical condition, marital status, citizenship status, military or veteran status, or any other basis covered by applicable laws. Mozilla will not tolerate discrimination or harassment based on any of these characteristics or any other unlawful behavior, conduct,