Site Reliability Engineer; Edge

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 more than 50 countries. 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  value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics.

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 tackles global challenges in traffic flow management, load balancing, and application service control at scale.

We embrace SRE principles—automation, reliability, and performance—to 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.

• Design, build, and operate resilient application and traffic management systems for Proton’s most critical production services.
• Develop and maintain automation tools to enhance deployment processes, configuration management, and service reliability.
• Ensure availability and performance of production services through load balancing, network optimization, and failure recovery strategies.
• Improve monitoring, alerting, and incident response to maintain high availability and rapid issue resolution.
• Optimize and scale Proton’s hybrid infrastructure, spanning on‑premises and cloud‑based deployments.
• Collaborate with product and security teams to implement best practices for privacy and data protection at every layer of the stack.
• Document and share knowledge to foster a culture of learning and continuous improvement within the team and beyond.

• Bachelor’s degree in Computer Science, a similar field, or equivalent practical experience.
• Strong knowledge of networking, including TCP/IP, DNS, and HTTP/HTTPS traffic management.
• Experience deploying, tuning, and maintaining high‑performance load balancing solutions (e.g., HAProxy, Envoy, Traefik).
• Familiarity with Kubernetes and container orchestration in production environments.
• Experience with software development…