Lead iOS Developer

About Us

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!

About Photos

Join the team building Proton Drive Photos, a private photo storage designed so your memories belong only to you. We’re creating the encrypted alternative to Big Tech photo platforms, combining consumer-grade UX with uncompromising privacy. If you want to build products used by millions while helping fix the internet, we’d love to meet you.

The Role

As an engineer on our Apple team you’ll build and ship feature

s across Proton’s apps on iPhone, iPad and macOS, working closely with product and engineers across the company to define what “great” looks like on Apple platforms. Our codebase is primarily Swift with some Go, and we’re moving to a platform-independent Rust logical core that communicates with Swift via a generic interface, so Rust experience is a strong plus. Quality is central to the role: you’ll contribute to and maintain our testing stack, including unit tests for business logic, stubbed API tests for pseudo-integration, snapshot tests for UI and XCUITest for end-to-end user flows. You’ll join a team that pairs deep technical expertise with an obsession for simple, usable interfaces, shipping privacy-preserving products used by millions.

What we are looking for:

• You have experience in iOS in particular with Swift
• You have a passion for mentoring other engineers and helping them grow
• You are passionate about user interaction, usability, and providing an excellent user experience
• Demonstrated experience driving change within an organisation and leading complex technical projects
• Extensive experience building maintainable and testable code bases, including API design and unit testing techniques

Extensive experience with concurrent programming and mobile memory management

A strong grasp of scalable software architecture and software engineering best practices

An intuition for optimal user experience and design

Rust experience not required, but a major plus

Deep understanding of APNs, UNUserNotificationCenter and iOS background execution (silent pushes, background app refresh, background URLSession), and how these impact app reliability

Experience building offline-first data flows with local persistence (Core Data, SQLite, Realm or similar) and conflict-free sync

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)
• A great Team: 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.

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 its 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 anonymise 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 CVs 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.