Senior Security Engineer, Bug Bounty at Mozilla in United Kingdom

Why Mozilla?
Mozilla Corporation is the non-profit-backed technology company that has shaped the internet for the better over the last 25 years. We make pioneering brands like Firefox, the privacy-minded web browser. Now, with more than 225 million people around the world using our products each month, we’re shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies. Our work focuses on diverse areas including AI, social media, security and more. And we’re doing this while never losing our focus on our core mission – to make the internet better for people.
The Mozilla Corporation is wholly owned by the non-profit 501(c) Mozilla Foundation. This means we aren’t beholden to any shareholders — only to our mission. Along with thousands of volunteer contributors and collaborators all over the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms.
About this team and role:
At Mozilla, we believe the internet is a global public resource—open and accessible to all. As a Security Engineer, you'll protect that vision by building, breaking, and hardening products that put people’s privacy and safety first. We are looking for a security engineer to own, manage and administer the Mozilla Web Bug Bounty program and work with Mozilla product and SIRT teams to ensure risk mitigation of security incidents and events.
What you’ll do:
Own and scale Mozilla’s web bug bounty program, including strategy, prioritization, KPIs, and continuous improvement
Act as the primary interface with external researchers and platforms (e.g., HackerOne), fostering a high-quality and trusted research community
Lead triage and technical validation of incoming reports across multiple intake channels (HackerOne, Bugzilla, email)
Drive end-to-end vulnerability remediation, partnering with engineering teams to ensure timely, effective fixes
Identify root causes and systemic issues, and influence long-term improvements in secure development practices
Collaborate with the Security Incident Response Team (SIRT) on active incidents and post-incident reviews
Perform targeted code reviews (primarily JavaScript and Python) during investigations and high-risk changes
Develop or leverage tooling to improve triage efficiency, signal quality, and program insights
What you’ll bring:
3+ years of demonstrated ability in a security engineering role.
Experience operating bug bounty programs, including enhancements, automation and scaling, and/or bug hunting
Practical experience working with modern cloud technologies (eg. Amazon Web Services, Google Cloud Platform, Heroku, Microsoft Azure, etc.)
Experience analyzing code and systems to move from vulnerability → root cause → prevention
Real-world experience in software development and/or engineering operations
Ability to develop your own tools as needed in a variety of programming languages (eg. Python, Go, Rust, Javascript, etc.) is a plus, but not required.
Strong communication, collaboration, and problem-solving skills, with the ability to influence and guide cross-functional teams.
Formal credentials are great, but real-world experience, curiosity, passion and a growth mindset matter more.
What you’ll get:
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)
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 you give us 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 understands that valuing diverse creative practices and forms of knowledge are crucial to and enrich 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. We 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, or purpose.
Group: D
#LI-REMOTE
Req ID: R3105
Hiring Ranges:
Remote UK
£66,000—£87,000 GBP