Mozilla is hiring a

Sr. Software Engineer – Layout (CSS and API Support)


Senior Software Engineer - Layout (CSS and API Support), Mozilla Corporation, Portland, Oregon: Improve Cascading Style Sheets (CSS) style system, within Mozilla’s Gecko Engine and design solutions for efficient implementation within the Firefox Browser Layout Architecture stack. Write code, browser tests, and specifications and build prototypes and reference implementations for the Firefox browser. Convert user feedback into actionable bug reports, feature designs, and input into the strategic direction of Web Platform to make Firefox more effective and efficient. Refactor existing code to optimize for Firefox performance, repair and update automated test scripts to adapt to changes in the codebase, and verify that released code is functioning correctly and efficiently.

Bachelor's in Computer Science required.

Must have three years of experience programming in C++, Python, Rust, and JavaScript.

Of experience required, must have one year of experience working in the Gecko browser engine or similar.

Must also have experience working with:

  1. CSS Shapes, CSS Transform, CSS Motion Path, CSS Easing, and CSS Sizing;
  2. Resize Observer Application Programming Interface (API) and Web Animation API; and
  3. Bugzilla or comparable defect management and workflow tool.

Experience may be gained concurrently.

Position may be eligible for telecommuting from anywhere in the United States.

Salary: $116,475.00 to $176,234.06 per year.

Apply online:

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 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.



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