Senior Test Engineer, AI Investments

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:

Firefox Desktop Test Engineering (DTE) is a geographically distributed team responsible for validating all critical browser areas, both core and new, through dedicated testing. We focus on representing the user, driving quality across Firefox, and supporting teams in delivering a user-friendly experience. As a Senior Engineer, you’ll drive AI testing projects (manual & automation), collaborate with cross-functional teams and advocate for testing and quality.

Our team is invested in fostering a culture of learning, growing strong leaders and building a collaborative work environment. We want to raise the performance bar with every hire and promotion. You could be the next great thing to happen to our team.

What you’ll do: 

• Develop and implement comprehensive Test Plans using a mix of manual and automated testing for AI Features in Firefox. Write, run, and maintain tests.
• Build tooling and frameworks to make testing easier and faster. Implement test automation for machine learning algorithms.
• Collaborate with various teams across the organization to solve complex technical problems that reduce tech debt, improve efficiency, and enable the delivery of high-quality code at high velocity.
• Help prioritize product testing and risk management, advocate for building robust systems and practices, and represent our end-users’ best interests.
• Contribute towards building a healthy team culture, be the go-to person for the vendor team members, and unblock others/provide feedback.
• Be a strong, opinionated advocate for testing and quality.

What you’ll bring: 

• 5+ years of experience in a test engineering role (e.g., SDET, Senior Test Engineer, Test Automation Lead).
• 3+ years of experience with Pytest, Selenium or similar frameworks.
• Proven track record of leading and executing AI/ML feature testing with expertise in both manual and automated UI testing. Skilled in validating AI-driven outputs, ensuring accuracy, reliability, and seamless user experience.
• Proficient in at least one programming language (Python, Javascript).
• Strong knowledge of SDLC and QA methodologies. Experienced in working with test case management and bug tracking tools.
• Experience leading delivery of projects with geographically distributed teams or vendor companies.
• Ability to quickly learn and implement unfamiliar technologies.
• Analyze and tackle sophisticated software development problems spanning multiple components, sometimes outside areas of expertise.
• Commitment to our values:
• Welcoming differences
• Being relationship-minded
• Practicing responsible participation
• Having grit

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 [email protected] 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

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Req ID: R2912