Site Reliability Engineer - Application Edge in London

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, 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.

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. 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. You will have the opportunity to work with many of the world's top minds in their fields. 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.

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 principles—automation, reliability, and performance—to develop and operate infrastructure that scales with Proton’s growing user base.

What You Will Do

• 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.

We Need You to Have

• Bachelor’s degree in Computer Science, a similar field, or the 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 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.

What We Offer

• Office First: Collaboration is easier and more effective in person, which is why we have offices in various locations. You can also enjoy working from home up to 30% of the time.
• Technology: We provide all the devices and software you need to excel in your role.
• Food: Lunch and snacks are provided by Proton every day at our offices.
• Transport: We support our employees with transport costs through subsidising public transport, bike allowances, or parking spaces based on your office location.
• Stock Options: 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.
• 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 that puts its users and community first in everything we do.

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 feel valued and empowered.

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