Full Stack Software Developer Contract Jobs in London, ON

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!

Drive Foundation

Drive Foundation is the backbone of Proton Drive. We ensure that cross-client initiatives are executed consistently and efficiently. Whether it's aligning multiple clients, maintaining documentation or the RFC process, or building robust SDKs, our team lays the groundwork that makes the entire Drive experience work seamlessly.

• Current Projects:
  • We're currently focused on developing SDK that encapsulate the core functionality of Proton Drive. The SDK comes with two core implementations, one in C# for desktop and mobile clients and second in TypeScript for web client, and higher-level modules in Rust. Our SDK primarily serve internal clients today, but our long-term vision includes integrating them across the Proton ecosystem-and even enabling third-party applications to interface with Drive.
• Tech Stack and Tools:
  • Languages we see daily is C#, TypeScript and Rust. We also need to provide bindings for Swift and Kotlin. 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, or GitLab in general to work on the code base.
• Future Plans:
  • We are planning to revamp our cryptographic model to boost performance and efficiency across all clients. We will finish ongoing first generation of SDK to cover all core Drive features and new crypto model. Then we will do second generation in Rust with lessons learned and include full support of all features such as Photos, Public Sharing, and Docs.
• Impact Opportunities:
  • Foundation work touches every aspect of Drive. The SDK and infrastructure you build will be used by every Drive client-and getting it right is both critical and deeply rewarding.
  • Drive is rapidly expanding. As it evolves into a true platform, we expect more teams to emerge-each owning different verticals built on top of Drive. This opens up immense opportunities to grow as an IC, tech lead or engineering manager.
  • You'll have the chance to shape not only the future of Drive, but also your own career path in a variety of domains and technologies.

As a Senior Drive Foundation Engineer, you will play a crucial role in designing, implementing, and maintaining the foundational components that power Proton Drive applications. You will work collaboratively with Drive teams, including backend, web, mobile, or desktop 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 C#/TypeScript/Rust libraries that serve as the backbone for Proton Drive's applications.
• Cross-platform compatibility: Ensure compatibility and optimal performance across various platforms.
• Code review and optimization: Conduct code reviews and provide constructive feedback to ensure code quality, maintainability, and performance optimization.
• Collaboration: Work closely with backend, frontend, mobile and desktop developers to integrate core libraries seamlessly into Proton Drive's applications.
• 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.

Job requirements:

• 5+ years of professional software development experience, with a focus on the Rust programming language.
• Strong expertise in Rust language features, concurrency, and ownership models.
• Web, mobile, and/or desktop development: Experience in developing libraries for client applications.
• Proven ability to work collaboratively in a team environment and excellent communication skills.
• Strong problem-solving skills and the ability to troubleshoot issues efficiently.

Even if you don't meet all the requirements listed above, but feel you could still be a great fit, please still apply.

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)
• Work with smart and dedicated people - Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world's top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• 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
• 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.
• 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.

#LI-ONSITE