Join Proton and build a better internet where privacy is the default At Proton, we believe that privacy is a fundamental human right and the cornerstone of democracy. Since our inception in 2014, founded by a team of scientists from CERN, we have dedicated ourselves to providing free and open-source technology to millions worldwide, ensuring access to privacy, security, and freedom online.
Our journey began with Proton Mail, the largest secure email service globally, and has since expanded to include Proton VPN, Proton Calendar, Proton Drive, and Proton Pass. These tools empower individuals and organizations to take control of their personal data, break away from Big Tech’s invasive practices, and defeat censorship. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations.
Proton today supports over 100 million user accounts with a growing team of over 500 people from over 50 different countries, from the world's top companies and universities. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online. We have a global mindset and big ambitions but remain a start-up at heart. We value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics. Check our social media pages to learn more about us: Twitter , Reddit , Instagram .
As Proton is a global Company, the Payments Team works to continuously expand the possibilities for users to pay with various payment methods, beyond just plain credit cards or Paypal.
The mission of the team is to empower anyone in the world who wish to use Proton services, to become a Proton subscriber by building enticing interfaces, being able to progressively reach integral markets, by providing the methods and tooling allowing users to pay, and for the Proton organization to properly being able to measure growth,



and to follow the relative financial regulations.
Differently than many other stacks at Proton, the Payments stack depends largely on external services such as payment providers, tax-information providers, currency-conversion providers... As such it is critical, for the success of the service, to build with resilience.
Our mobile code is based on Kotlin (on Android) and on Swift (on iOS), with a growing shared codebase in Rust.
We are migrating our infrastructure to Kubernetes.
Everything runs on premise in Proton's data-centers.
To organize our work we use classic tools such as Jira and Confluence.
With payments being the backbone of any subscription business, we have ambitious plans to expand the team to cover a wide breadth of topics ranging from demystifying payment performance data across regions/products, to thinking about the holistic strategy of product catalogs, and everything in between. This particular team requires someone who is a strong generalist, who thrives with ambiguity. You will be the main Senior Android Engineer building our payments solution which plays a key part of the Proton product ecosystem. You must be capable of building a highly secure and reliable Android app that will be used by millions from around the world. You will have the opportunity to play Product or Project Managers roles and lead the whole development and testing process.
Deep experience with Kotlin
Deep understanding of advanced Android UI design principles, patterns, and best practices
Experience with secure coding practices




Excellent English communications, both written and spoken
Familiarity with cryptocurrencies (Bitcoin), payment systems, and blockchain technology
Knowledge of Rust
Office First: You can also enjoy working from home up to 30% of the time, while enjoying great company during our three core days in the office.
Technology: We provide all the devices and software you need to excel in your role, ensuring you have the best tools at your disposal to achieve your goals.
Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location.
Flexible Working: You can define your own working hours as long as it works with team meetings.
Proton offers various learning opportunities, including training programs, conferences and events, and continual learning.
Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs.
Check our social media to learn more about Proton:

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

📌 Senior Android Engineer, Payments - Kotlin & Global Growth (Barcelona)
🏢 Proton
📍 Barcelona