Senior Android Engineer (Pass)

Proton

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. Role overview As a fullstack cross-platform Android Engineer, you'll play a pivotal role in developing Proton Photos using Jetpack Compose and Rust. You’ll use an end-to-end ownership approach, ensuring timely delivery of high-quality, scalable solutions that will delight our customers.  Key responsibilities * Develop and maintain cross-platform mobile applications for Android using a blend of cross-platform (Rust) and native technologies (Kotlin) * Take end-to-end ownership of mobile application development projects: you'll be comfortable with scoping projects, walking back from deadlines and being able to discern the important from the superfluous * Foster a culture of innovation by exploring new technologies, methodologies and approaches to mobile development – we tackle complex engineering challenges with creativity and ingenuity * Optimise mobile applications for performance, usability and responsiveness across different devices and screen sizes * Master memory management, multithreading and concurrency mechanisms to enhance performance and responsiveness of mobile applications * Design for scalability, considering factors such as data caching, network bandwidth and server load * Prioritise customer satisfaction by maintaining a customer-centric mindset throughout the development process, continuously seeking feedback and iterating to improve the user experience The ideal candidate will bring * Bachelor's degree in Computer Science, Engineering or related field (or equivalent work experience) * Excellent problem-solving skills and the ability to think outside the box to overcome challenges * Passion for continuous learning and driving change in the rapidly evolving field of mobile development * Excellent communication and interpersonal skills * Proven experience developing mobile applications for Android using Kotlin * Proficiency with Jetpack Compose for Android, and familiarity with Rust * Strong understanding of mobile app architecture, design patterns and best practices * Knowledge of memory management techniques and best practices * Experience with multithreading and concurrency in mobile applications * Good understanding of scalability considerations when it comes to engineering mobile applications * Previous experience working in a fast-paced, scale-up environment Even if you don’t meet all the requirements listed above but feel you could still be a great fit, please do apply. What we offer * 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 * Learning & Development: we are committed to your professional growth – Proton offers various learning opportunities, including training programs, conferences/events and continual learning * Employee Benefits: comprehensive health insurance plans, competitive retirement savings options, generous vacation/leave policies and wellness programs * Stock Options: at Proton, we are all owners of the company and you get stock options when you join us * In-Person Collaboration: collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje and Taipei – you can enjoy working from home for up to 30% of the time, while enjoying great company culture during our three core days in the office * Food: lunch and snacks are provided by Proton every day at our offices * Transport: we'll always support our employees with transport costs through subsidising 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 * Work that Matters: Proton is a community-first organisation, started with the support of a crowdfunding campaign and built with community input – to this day, Proton’s only source of revenue is user subscriptions: over 100 million people trust and support Proton, and we put our users and community first in everything we do (read more about our impact here) 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. To learn more about our privacy policy, please visit our privacy policy page. #LI-ONSITE

Proton

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 Payments Team The goal of the Payments team is to enable revenue generation for the entire Proton ecosystem. This comes in the form of introducing new payment methods for users to architecting our client libraries. This team has impact across all of Proton's products and is critical to the success of the business as a whole. * 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 team works in tight collaboration with the Account Team (responsible for the Proton user lifecycle), the Proton Finance team, and every single Business Unit to ensure that plans, promotions and pricing meet user expectations. * 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 global 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 Tech Stack and Tools: * 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. * Internally our backend code is in general based on PHP/Symfony, our frontend is based on React, our mobile code is based on Kotlin (on Android) and on Swift (on iOS), with a growing shared codebase in Rust. * All our client-code is open-source and GPL3. * 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. Future Plans: * 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. There's huge potential for growth no matter the domain, and the outcome for any candidate is an in-depth view into how money moves globally. What you will do: * Build features in all of Proton's products. * Close interactions with products and engineers across the company. * Build scalable software architecture through software engineering best practices. * Optimise user experience and design. Job requirements: * Proven experience with back-end development  * Expertise in building scalable, high-performance solutions * Proficiency with profiling techniques and performance optimization tools * Experience leading a team initiative from discovery to production * Strong understanding of SQL (MySQL preferred) and data modeling best practices * Familiarity with Redis or other caching technologies for performance optimization * Knowledge of security best practices and experience implementing secure software solutions * In-depth understanding of HTTP/REST, including both the development and consumption of web-based APIs * Solid grasp of cryptographic concepts, including key exchange, and the distinction between symmetric and asymmetric encryption Bonus points for:  * Experience within the payments domain 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, Zürich, 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. COMPENSATION RANGE * Paris: 53,000 - 82,000 EUR gross annually* * Other locations: Compensation will be discussed during the interview process.  * Final compensation will be determined based on the candidate's qualifications, skills, and previous experience.   #LI-ONSITE

Proton

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. Our work impacts hundreds of millions of lives, from activists on the front lines defending freedom to leaders in governments protecting sensitive information. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations. Proton is a profitable company that does not rely upon VC funding, supporting 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. We value intelligence, learning potential, and ambition in our hiring process. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online. Hiring at Proton is highly selective, with less than 1% of candidates hired. We believe smaller teams of exceptional talent will always prevail over larger teams with lower talent density. You will have the opportunity to work with many of the world's top minds in their fields, ranging from former international math and science olympiad winners to chess champions. 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. Tired of blending into the crowd? Join us and do work you can truly be proud of. Check our open-source projects here! The team: Proton VPN enables millions of people to connect securely and privately, even in places where the internet is restricted or unreliable. Delivering that experience means our service must perform flawlessly under highly variable, real-world conditions. We are looking for a Senior Performance Engineer to lead our efforts in making Proton VPN the fastest, most resilient, and most reliable VPN service in the world. You will define and drive the measurement, analysis, and optimization of Proton VPN’s end-to-end performance, across clients, platforms, and global infrastructure. You’ll help ensure that every connection is fast, stable, and private, regardless of where the user is or what network they’re on. What you will do:  * Design and own Proton VPN’s performance framework, defining metrics and KPIs that reflect the real-world experience of users (time-to-connect, throughput, latency, stability, reconnection rates, etc.). * Develop distributed testing systems that simulate real network conditions, including low bandwidth, packet loss, and high-latency scenarios. * Continuously measure and analyze performance across platforms (desktop, mobile, backend) and regions to identify bottlenecks and regressions. * Collaborate with backend, R&D, and client teams to optimize protocol handling, connection setup, routing, and encryption performance. * Create dashboards, reports, and automated alerts to track global performance health. * Contribute to the design of resilient connectivity strategies that adapt dynamically to variable network conditions. * Serve as the performance champion within the engineering organization, mentoring others and driving a data-driven performance culture. Job requirements:  Technical Skills * 5+ years of experience in performance engineering or systems QA, ideally in networking, VPNs, or distributed systems. * Knowledge of network protocols (TCP/IP, UDP, TLS, WireGuard, debugging, manipulating, and performance profiling tools. * Proven ability to analyze latency, throughput, and stability metrics across multiple layers (client, OS, transport, application). * Proficiency in Python (or similar scripting language) * Familiarity with network emulation and simulation tools (e.g., tc/netem, iperf, IPTables/nfTables…). * Experience with monitoring and observability stacks (Grafana, Prometheus, Loki) and CI/CD pipelines. * Cross-platform experience with Linux, macOS, Windows, Android, and iOS preferred. Bonus points for:  * Experience with Rust/C/C++/System development Soft Skills * Analytical and methodical, yet creative in solving complex performance problems. * Comfortable working with uncertainty and non-deterministic conditions. * Collaborative mindset, able to work across client, infrastructure, and data teams. * Strong communication and documentation skills in English.   What We Offer * Office First: Collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje, and Taipei. 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. * Food: Lunch and snacks are provided by Proton every day at our offices. * Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location. * Stock Options: At Proton, we are all owners of the company and you get stock options when you join us. * Flexible Working: You can define your own working hours as long as it works with team meetings. * Learning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning. * Employee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs. * Work that Matters: Proton is a community-first organization, started with the support of a crowdfunding campaign and built with community input. To this day, Proton’s only source of revenue is user subscriptions. Over 100 million people trust and support Proton, and we put our users and community first in everything we do. Read more about our impact here. 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