Senior Security Engineer, Subscriptions & Fraud Remote US

Company: Mozilla

Why join Mozilla engineering?

Learn: Code review at Mozilla includes pushing to passionate contributors around the world. Building Firefox and its family of products requires knowledge up and down the stack, and extremely high standards for security and optimization. Beyond the browser, we’re developing AR/VR, IoT, and voice recognition products that respect and protect privacy.

Grow: We’re dedicated to helping every team member develop. We give engineers trust and responsibility from day one, offer generous stipends for learning opportunities, and provide mentorship, especially around key leadership skills like collaboration and clear, kind communication.

Make Your Mark: We’re small but mighty, challenging the biggest behemoths on the internet with a staff the size of their marketing departments. That means every engineer can have an outsized impact on products that touch tens of millions of users—ultimately influencing how the entire internet works.

The Role

Mozilla’s Firefox Operations Security Team is looking for a Security Engineer to increase the security of our Firefox services, particularly our upcoming billing and subscription services. We are looking for someone with strong web application security skills, experience implementing cloud services and preferably payment systems, and a deep understanding of fraud detection techniques. You’ll be hardening our environments by working closely with the teams responsible for engineering and hosting backend services for Firefox. You will provide hands-on technical engineering of our fraud detection pipeline to support an ever-growing set of services and application environments.

Most importantly, you will become a core member of the team responsible for protecting Firefox, and keeping Mozilla's users safe on the Internet.

As a security engineer at Mozilla, you will…

  • Run security reviews and audits of new and existing services
  • Develop and implement a fraud detection techniques to detect payment fraud and subscriptions abuse
  • Own the adoption of modern authentication, authorization and cryptographic techniques
  • Automate security testing and auditing to prevent regressions and catch issues before they reach production
  • Work with developers and operators across the organization to keep the Firefox backend infrastructure safe

Your Professional Profile

  • You have a passion for crafting security controls into the core of complex systems
  • You have worked on, or close to, PCI compliant environments
  • You're a strong communicant who's not afraid to cross team boundaries to get projects to succeed
  • You have fortified cloud infrastructure, built security at all levels of the stack, defined security perimeters, implemented cryptographic algorithms, access controls, account management, etc
  • You're comfortable working in both software engineering and operational teams, and have a complete understanding of Agile and DevOps principles.
  • You love programming and building new things. Experience in Java and Python is preferred, but we also work with Go, Javascript and Rust.
  • A minimum of 5 years experience in a security engineering role is required. A B.S. in Computer Science would also be lovely. 

Feel good about your work again.

At Mozilla, we’re serving humanity—by maintaining a safe, open internet—while also helping the individual humans employed here to reach their personal and professional goals. With a relatively small team serving hundreds of millions of people, a culture of exploration, and a commitment to mentorship, opportunities abound to learn and grow at Mozilla.

Our values drive our actions

  • Purpose is built into our work, with our mission driving every decision
  • We challenge assumptions, the status quo, ourselves, and each other
  • We are transparent: in our code, our business partnerships, and our everyday interactions 
  • We seek out people from diverse backgrounds and with perspectives different from our own 
  • We pair purpose with performance and put people ahead of profit


Our impact is global

  • 1000+ paid staff from over 30 countries
  • Thousands of volunteer contributors across six continents
  • 10 global offices: Beijing, Berlin, London, Paris, Mountain View, Portland, San Francisco, Taipei, Toronto and Vancouver
  • Hundreds of home offices globally


Our benefits are world-class 

  • Flexible work environment (nearly half of Mozillians work remotely)
  • Industry-leading paid parental leave (up to 26 weeks of fully paid leave for childbearing parents and up to 12 weeks for non-childbearing parents)
  • Reimbursement for professional development (up to $3,000/year)
  • A work setup including the latest hardware and software of your choice
  • Wellness programs—we reimburses up to $1700/year for expenses like child and elder care, mental wellness, and personal enrichment 

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. Join us to work on the Web as the platform and help create more opportunity and innovation for everyone online.

A lot of companies say they’re “mission-driven.” Our unique corporate structure guarantees that every decision we make upholds our mission: to make sure the internet stays available, safe, and welcoming to everyone. Beholden to neither shareholders nor investors, Mozilla Corporation is wholly owned by the not-for-profit Mozilla Foundation.

Along with 20,000+ volunteer contributors and collaborators all over the world, Mozilla Corporation’s staff designs, builds, and distributes software that allows people to enjoy the internet on their own terms. Our flagship product — the Firefox browser — has expanded into a family of products that protects users and alerts them of risks. Mozilla’s Emerging Technologies group incubated and sponsors Rust — Stack Overflow’s “most loved programming language” for the last four years — and is building safe, private versions of virtual reality, internet of things, and voice recognition.


Group: D


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