Mobile Software Developer Jobs in London, ON (NOW HIRING)

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we've built the world's largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar-tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

The team:

Drive Foundation is the backbone of Proton Drive. We develop the Proton Drive SDKs, the core of all of Proton Drive's client applications as well as the cornerstone of Drive into other Proton applications, businesses, and 3rd parties. We ensure that cross-client and backend initiatives are executed with consistency and correctness; we also build and maintain the core documentation for Drive and define the architectural roadmap to evolve Drive's technology, both server-side and client-side.

• We use standard tools for communication and work organization (Git, GitLab, GitHub, GitLab CI, Jira, Confluence). Languages we see daily is C# and TypeScript. We also need to provide bindings for Swift and Kotlin, and we plan to add Rust to avoid the need to have two SDK implementations. We use Grafana and Prometheus to instrument our SDK, Sentry to get details issues from the SDK usage, GitLab CI for running tests including e2e tests written using Playwright for both SDKs, or GitLab in general to work on the code base.

Purpose of the role:

As a Senior Rust Developer on our team, you will play a crucial role in designing, implementing, and maintaining components that power Proton Drive. You will work collaboratively in a cross-functional team, including backend API, web frontend, Mac, Windows, and Android/iOS mobile developers, to ensure seamless integration and optimal performance across various client applications.

What you will do:

Architect and develop core libraries: Lead the design and development of core Rust libraries that serve as the backbone for Proton web and mobile applications.
Cross-platform compatibility: Ensure compatibility and optimal performance across various platforms, including web browsers and mobile devices.
Code review and optimization: Conduct code reviews and provide constructive feedback to ensure code quality, maintainability, and performance optimization.
Collaboration: Work closely with frontend and mobile developers.
Security: Implement and adhere to best practices in secure coding to maintain the high level of security and privacy Proton is known for.
Testing: Develop and implement comprehensive testing strategies, including unit tests and integration tests, to ensure the reliability of core libraries.
Documentation: Create and maintain thorough documentation for core libraries to assist other developers in understanding and utilizing the components.
Continuous learning: Stay updated on the latest advancements in Rust and related technologies to suggest improvements and innovations.

Job requirements:

Experience: 5+ years of professional software development experience, with a focus on the Rust programming language.
Rust proficiency: Strong expertise in Rust language features, concurrency, and ownership model.
Web and/or mobile development: Experience in developing libraries for both web and mobile applications.
Collaborative skills: Proven ability to work collaboratively in a team environment and excellent communication skills.
Problem-solving: Strong problem-solving skills and the ability to troubleshoot issues efficiently.
Security focus: Understanding of secure coding practices and a commitment to maintaining high levels of security and privacy.
Version control: Proficient in using version control systems, preferably Git.
Bachelor's or Master's degree: In Computer Science, Software Engineering, or a related field.

Bonus points for: 

• Mobile development background: Experience with iOS (Swift) or Android (Kotlin) development, particularly building native mobile SDKs or integrating Rust libraries into mobile codebases.

What we offer:

What We Offer

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users - not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here)

• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.

• Technology: you'll get the right hardware and the right software you need to do your best work.

• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.

• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day

• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zurich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building

• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.

• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.

• Flexible Working: you own your schedule. Set hours that work for you and your team - because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch.

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.

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