Site Reliability Engineer (Application Edge)

London; Prague; 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 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 ouropen-sourceprojectshere! Purpose of the Role: As a Site Reliability Engineer on the Application Edge team at Proton, you will help build, maintain, and scale the critical infrastructure that powers our privacy-focused services. We manage user-facing production infrastructure across both on-premises and cloud environments, ensuring the reliable, secure, and high-performance delivery of Proton’s most critical traffic. Our team is at the forefront of private infrastructure technology, tackling global challenges in traffic flow management, load balancing, and application service control at scale. We embrace SRE principles94automation, reliability,94and performance94to develop and operate infrastructure that scales with Proton’s growing user base. If you want to thrive in a high-impact role where infrastructure meets privacy,this is an opportunity to contribute to one of the most security-conscious and performance-critical environments in the industry. What You Will Do:

• Design,build,and operate resilient applicationand traffic management systems for Proton’s most critical production services.
• Developand maintain automation tools to enhance deployment processes,configuration management,and service reliability.
• Ensure availabilityand performance of production services through load balancing,network optimization,and failure recovery strategies.
• Improve monitoring,alerting,and incident response to maintain high availabilityand rapid issue resolution.
• Optimizeand scale Proton’s hybrid infrastructure,97spanning on-premises97and cloud-based deployments.
• Collaborate with product97and security teams to implement best practices for privacy97and data protection at every layer of the stack.
• Document97and share knowledge to foster a culture of learning97and continuous improvement within the team97and beyond.

We Need You to Have:

• Bachelor’s degree in Computer Science,97a similar field,97or the equivalent practical experience.
• Strong knowledge of networking,97including TCP/IP,97DNS,97and HTTP/HTTPS traffic management.
• Experience deploying,97tuning,97and maintaining high-performance load balancing solutions (e.g., HAProxy,97Envoy,97Traefik).
• Familiarity with Kubernetes and container orchestration in production environments.
• Experience with software development and automation in one or more programming languages (e.g., Python, Rust, Go).
• Ability to troubleshoot complex production issues across network, application, and system layers.
• A strong security mindset, with an understanding of secure infrastructure practices.

Bonus Points For:

• Hands-on experience with traffic shaping, rate limiting, and DDoS mitigation strategies.
• Deep expertise in Kubernetes service optimization and management.
• Experience with Infrastructure as Code (Terraform, Ansible or similar).
• Familiarity with privacy-focused infrastructure challenges and solutions.

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

• Office First: Collaboration is easier and more effective in person; offices are located in Geneva; Zurich; Prague; Barcelona; Paris; London; Vilnius; Skopje; Taipei. Work from home up to 30% while enjoying great company during three core days in office.
• Technology: All devices/software needed provided for role excellence.
• Food: Lunch/snacks provided daily at offices.
• Transport:Support for transport costs via subsidized public transport/bike allowances/parking based on office location.
• Stock Options: All employees get stock options upon joining.
• Flexible Working:Define own working hours compatible with team meetings.
• Learning & Development:Various learning opportunities including training programs/conferences/events/continuous learning.
• Employee Benefits:Comprehensive health insurance plans/competitive retirement savings/generous vacation & leave policies/wellness programs.
• Work that Matters:Proton is community-first organization funded by user subscriptions trusted by over 100 million people putting users/community first always.

Our Commitment to Diversity & Inclusion Proton believes diversity drives innovation strengthening mission for privacy as default for all. Committed fostering inclusive environment where all individuals regardless race/ethnicity/gender/age/sexual orientation/physical ability/socio-economic background feel valued empowered. Create equal opportunities/promote open dialogue/support continuous learning ensuring every voice heard respected. If extra support or reasonable adjustments needed during hiring process please inform talent partner. Candidate Privacy Notice Applicant information stored in Greenhouse per their Service Privacy Policy used for evaluating suitability for posted position also retained for future roles consideration aligned with background/skills. Data deleted/anonymized when no longer needed. Inquiries about data use/access/correction/deletion directed to careers@proton.ch. Proton does not accept unsolicited resumes except directly from candidates; no fees paid for unsolicited offers even if candidate hired. For more about privacy policy visit our privacy policy page.

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