INTERNSHIP DETAILS

Firefox Software Test Engineering Student Worker

CompanyMozilla
LocationGermany
Work ModeRemote
PostedMay 6, 2026
Internship Information
Core Responsibilities
Develop and maintain automated testing frameworks and scripts for the Firefox Desktop Browser. Collaborate with engineers to implement monitoring systems and support CI efforts using Taskcluster.
Internship Type
full time
Company Size
1755
Visa Sponsorship
No
Language
English
Working Hours
40 hours
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About The Company
A lot of companies say they’re “mission-driven.” Our unique corporate structure guarantees that every decision we make upholds our mission: to ensure the internet remains open and accessible. Beholden to neither shareholders nor investors, Mozilla Corporation is wholly owned by the not-for-profit Mozilla Foundation. Along with our communities of 20,000+ contributors and collaborators, 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, safeguards passwords and provides a secure VPN (with more to come). By maintaining a safe, open internet we're helping humanity, 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.
About the Role

The Opportunity

The Firefox team is a community of engineers who care deeply about delivering the fastest, friendliest, and most usable browser possible. We are responsible for making the things you see in the browser work securely, quickly, and well!

Our team is geographically distributed and responsible for validating all critical browser areas, both core and new, through dedicated processes for build validation, new feature testing, regression testing, end-to-end testing, and bug work. Our focus is on being the voice of our users and helping to fix things in Firefox as well as assisting other teams in making it the most user-friendly browser on the market. We are currently working on building a system to automate the majority of our smoke tests and implementing a monitoring system.

Do you enjoy delighting people with solutions to their problems? Do you like to collaborate with engineers and learn from others? Are you interested in learning how to write performant, secure code and deliver it to hundreds of millions of people? If so, we’d love to hear from you.

What You'll Get To Do

  • Work on one of the world’s largest and most important open source codebases - the Firefox Desktop Browser.
  • Work with a world-class engineering organization solving internet problems. 
  • Your work will positively affect hundreds of millions of folks worldwide.
  • Collaborate with other engineers to set up automation framework and write scripts
    • Create Page Object Models and support scripts for automated testing
    • Write automated tests, do code reviews of Page Object Models, support scripts, and automated tests.
    • Support CI efforts with Taskcluster.
    • Assist in the creation/maintenance of a test monitoring system.
    • Assist your team by investigating and resolving technical challenges.
    • Contribute to QA Automation best practices.

What You Bring

Enjoy working with a geographically dispersed team, people from different time zones, cultures and backgrounds.Know how to identify a problem, come up with a logical solution, and use the knowledge to tackle similar problems in future.

  • Proactively identify opportunities to assist with tasks and challenges to enhance team collaboration.
  • Detail-oriented with a passion for quality and testing.
  • Ability to learn quickly and adapt to new technologies and methodologies.
  • Speak English fluently and enjoy conducting software engineering work in the open.

You will help us to improve the user experience of Firefox and the web in general. We offer flexible working hours and competitive compensation depending on the number of hours. You will be able to participate in our office life, including catered lunches and various social activities.

Qualifications

  • Experience with Python programming language.
  • Familiarity with Selenium or similar WebDriver for test automation.
  • Basic understanding of Continuous Integration and Continuous Deployment (CI/CD) practices.

Bonus Points

  • Familiarity with PyTest testing library.
  • In-depth understanding of Continuous Integration and Continuous Deployment (CI/CD) practices.
  • Basic or above knowledge of AI tools 
  • Familiarity with Taskcluster or similar CI services
  • Unafraid of asking questions, and proposing new ideas if you think they will make a positive impact.
  • A love of helping your colleagues grow and get better at what they do.

We value a variety of voices within our team and at Mozilla. You don't need to check every box on this list to apply.

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.

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 recruiting@mozilla.com to request an 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.

Key Skills
PythonSeleniumWebDriverCI/CDPyTestAI ToolsTaskclusterAutomated TestingPage Object ModelRegression TestingSmoke TestingCode Review
Categories
SoftwareTechnologyEngineering
Benefits
Flexible Working HoursCompetitive CompensationCatered LunchesSocial Activities