Software Engineer, Firefox Desktop Integrations

Mozilla; Toronto; On-site; CAD 82,000 - 110,000; Full time

Benefits offered by this job

Bonus program

Medical/dental/vision

Retirement plan

Wellness days

Home office stipend

Professional development

Parental leave

Referral bonus

Job summary

Mozilla Canada, Toronto, is seeking a Software Engineer who is early in their career and eager to grow. You will contribute to Firefox features, work on desktop integration tasks across Windows and macOS, and collaborate with peers to deliver reliable, high‑quality code.

You will learn through guidance, participate in code reviews, and help grow our open and inclusive engineering culture while building features that reach millions of users.

Qualifications

• Proficiency in at least one of C++, Rust, or JavaScript.
• Experience building software on a major desktop platform (Windows/macOS/Linux).
• Strong communication and collaboration skills.

Responsibilities

• Build and maintain Firefox features that enhance value and engagement.
• Implement product experiments with feature flags and telemetry.
• Work on platform-specific challenges on Windows and macOS.
• Collaborate with product, design, and data science to define goals.
• Participate in code reviews and fix bugs.
• Engage with a distributed team and open culture.

Skills

C++

Rust

JavaScript

Desktop applications

User-focused

Communication

Team collaboration

Tools

Win32 API

Telemetry platforms

SQL

Job description

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.

About This Team

The Firefox team is a community of engineers who care deeply about delivering the fastest, friendliest, most usable browser possible. We are responsible for making the things you see in the browser work securely, quickly, and well! Desktop Integrations is part of Firefox Growth: a cross‑functional team of engineers, product managers, designers, and data scientists focused on helping more people discover, choose, and keep coming back to Firefox.

We build the places where Firefox meets the operating system: notifications that reach people even when Firefox is closed, pinning web apps to the taskbar, launch on login, and making Firefox the default browser on Windows and macOS. We ship these as experiments, measure their impact on engagement, and double down on what works.

Our team is geographically distributed, and working in the open is the norm. We contribute to the code driving the Firefox browser on all desktop platforms.

About The Role

A Software Engineer is an early‑career individual contributor who is growing in their ability to take on more complex tasks. At Mozilla, this role involves working on engineering projects that typically span several weeks and require collaboration with peers. Software Engineers at this level contribute to implementation, ask thoughtful questions, and raise blockers early. They communicate clearly within their team, follow team processes, and steadily build expertise in their domain.

What You’ll Do

• Build and maintain Firefox features that help people get more value from Firefox and keep coming back, from OS notifications to taskbar and startup integrations.
• Implement product experiments with guidance from senior engineers, including feature flags, targeting, and telemetry, so we can measure what actually moves engagement.
• Work on platform‑specific challenges on Windows and/or macOS where Firefox interacts directly with the operating system.
• Partner with product, design, and data science to understand the goal behind each feature and how its success will be measured.
• Collaborate with your manager and teammates to define and scope tasks, with regular check‑ins to share progress and ask for support when needed.
• Participate in code reviews to grow your understanding and contribute to a high‑quality codebase.
• Help identify and fix bugs that improve the Firefox experience for our global user base.
• Engage with a distributed team and contribute positively to our open and inclusive work environment.

What You’ll Bring

• Proficiency in at least one of C++, Rust, or JavaScript, and willingness to learn the others.
• Some experience building software that runs on a major desktop platform (Windows, macOS, or Linux).
• Curiosity about users and impact: you care whether a feature is used, not just whether it ships.
• Willingness to communicate clearly, ask questions, and seek feedback.
• Ability to contribute to collaborative projects and steadily build up your technical and problem‑solving skills.
• A growth mindset and enthusiasm for contributing to impactful software.

Bonus Points

• Exposure to native Windows or macOS APIs (such as Win32, WinRT, or Cocoa).
• Experience with A/B testing, feature flagging, or product analytics.
• Familiarity with SQL or working with telemetry data.
• Previous participation in open source projects or a strong interest in learning how to contribute.

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.

What You’ll Get

• Generous performance‑based bonus plans to all regular 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 [e-mail] 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: E

Req ID: R3253

Hiring Ranges

Canada Tier 1 Locations

$82,000—$110,000 CAD

Canada Tier 2 Locations

$74,000—$99,000 CAD