Senior Engineer (Tech Lead), Android, (Mail)

Job description

A better internet, where privacy is the default, is possible. Building this better internet might seem daunting or even unthinkable, but at Proton, this is what we do every day.

Proton was founded in 2014 by a group of scientists who met at the European Organization for Nuclear Research (CERN). Our first product, Proton Mail, is now the world’s largest encrypted email service. Subsequent Proton products, such as Proton VPN, Proton Calendar, and Proton Drive, give our users full control over how and with whom their data is shared.

Today, Proton makes privacy universally accessible. Journalists from outlets like The Guardian and The New York Times, some of the world’s largest organizations, and people in more than 180 countries have signed up for over 70 million accounts. Our diverse and dynamic team is made up of more than 400 members representing over 40 different nationalities. While we are based in Geneva, Switzerland, we have offices in Zurich, Prague, London, Vilnius, Skopje, Taipei, and many more employees working remotely around the world.

Join one of Europe’s fastest-growing companies to help us solve challenging problems and build new products that will reach hundreds of millions of people. We want to create more than just one of the world’s most impactful tech companies; we want to create a new internet that serves the interests of all people. We need you, your voice, your ideas, and your ambition to make it happen.

Purpose of the role

ProtonMail Android app is our biggest client app used by millions of people everyday. We are currently operating a complete re-write of the app, while still providing support for the current production app. For this, Proton is looking for a strong senior Android engineer to be responsbile for the technical direction of our end-to-end encrypted mail app. As a tech lead in Proton, you will be leading the technical decision-making of the re-write project as well as keep on solving complex technical / design challenges, and implement best practices in code quality/architecture to ensure reliable and fast customer experience for our users. You will be joining a great team of 4 Android engineers distributed across Europe and using the latest technologies, frameworks, and methodologies such as Kotlin, Android SDK, Compose, Coroutines, Clean Architecture, etc. The team works closely together, support each other and continuously learns and improves. You will also be partnering with a Product Manager, a QA and a designer.


What you will do 

  • Drive the technical decisions in the team.
  • Define and maintain a clear and shared architectural vision for the app.
  • Design, develop and lead the implementation of new features.
  • Take the initiative to address current and mitigate potential problems.
  • Be accountable for the technical output of the team.
  • Effectively communicate with a cross-functional audience.
  • Encourage a culture of technical excellence through code reviews, mentoring and knowledge sharing.
  • Actively participate in the Proton Android chapters where we share knowledge and discuss all things related to the platform and innovation. 

Job requirements

  • Minimum 8-10 years of experience in Android native development.
  • A proven track record of leading development on and successfully launching a complex Android application.
  • Expert knowledge of Kotlin, Android SDK, Room, Coroutines, whole application lifecycle.
  • Highly skilled in writing clean, testable, high-quality code.
  • Solid familiarity with offline-first (optimistic) UX/UI.
  • Care about highly maintainable code, architecture, and testability.
  • Passion for user interaction, usability, and providing an excellent user experience.

Bonus points for 

  • Well versed in security and with a good understanding of security best practices from an application development standpoint. 
  • Experience using DevOps processes and practices (including CI/CD).
  • Experience working in a distributed team.

Why you should join Proton

  • Be part of a movement - Proton is not just a product or service but a community-driven movement united by a shared vision of online freedom. Our services are open source, audited, and supported by community contributions. We give back to our community by maintaining core encryption libraries and by supporting other organizations furthering the same goals as us.
  • Proton is free, open source, neutral, independent, and community first, while remaining financially sustainable.
  • 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.
  • Join a strong brand - Our encrypted email service - Proton Mail - has grown to be a staple of online security and privacy. Proton has been featured in multiple popular television and film productions, such as Mr. Robot, Knives Out, Sounds of Metal, and more.
  • Grow with us - We’re one of Europe’s fastest-growing startups, doubling in size every year. Our growth gives you limitless career and educational opportunities as well as the opportunity to work side-by-side with many world-leading experts in their fields.
  • Have your voice heard - We value your opinion and encourage you to speak up and share your ideas and thoughts. At Proton, no problem is someone else’s problem. We collectively strive to do the right thing and be the undisputed best in the world at everything we do.
  • Benefits – these vary by location and type of contract but expect support on your vacation, parental leave, refreshment if working from the office, learning and development opportunities, equity for shared success, flexible working hours and remote work, company events and team building activities.


Proton uses the Recruitee recruitment platform for a more effective hiring process and a better candidate experience. Your data will always be kept confidential and is not shared with any third parties. Keep in mind that you will receive emails from the email address careers@protonmail.recruitee.com or other addresses on the protonmail.recruitee.com domain.
Proton does not accept unsolicited resumes from any sources other than directly from a candidate. Proton will not pay a fee for any placement resulting from the receipt of an unsolicited offer, even in a situation when the relevant candidate is employed by Proton.
By applying to a role at Proton, you acknowledge that we will process and store your personal data for at least the duration of the hiring process and as necessary to enter a contractual relationship with you.