Senior Site Reliability Engineer - VPN Service | NordVPN

NordVPN operates a globally distributed VPN and DNS infrastructure serving millions of users. The role involves deploying, managing, and improving VPN nodes worldwide while ensuring every client connection is fast, stable, and secure. The candidate will work closely with application teams to guarantee smooth client connectivity end to end, focusing on quality and reliability.

• Own critical VPN services end-to-end including architecture, scalability, security, and monitoring
• Deliver OKRs and key commitments within agreed timelines
• Write RFCs/ADRs for new features and refactors
• Raise engineering quality through standards, design reviews, knowledge sharing, and mentorship
• Balance reliability, security, and delivery speed with strong operational judgment
• Advanced networking knowledge including VPN protocols, tunneling, routing, and DNS
• Deep Linux knowledge including kernel internals, tuning, and module management
• Firewall management experience
• Performance analysis skills including flamecharts, profiling, and bottleneck identification
• OSI model fluency (L2 through L7), TCP/IP stack, SSL/TLS
• Security fundamentals including PKI, certificate management, and hardening
• Authentication and authorization experience with RADIUS and access control
• Configuration management and automated deployments
• Load balancing and failover for distributed services
• Experience with Docker

Nice to have:

• Python programming
• C, Rust, or Go for lower-level service and performance work
• Observability knowledge including monitoring, metrics, and logging for VPN services
• On-demand bare-metal/hardware provisioning
• Experience with eBPF, strace, and advanced debugging/tracing tools
• Virtualization experience with KVM, MicroVM
• Kubernetes networking
• Interest in AI tooling such as Claude Code, agentic engineering, and LLM integrations in engineering workflows

• Deploy and manage globally distributed VPN and DNS services
• Ensure connection quality, stability, and performance across the entire node fleet
• Collaborate with application teams on client connectivity and protocol behavior
• Optimize VPN service performance including kernel tuning, flamechart analysis, and profiling
• Manage security posture including firewalls, PKI, certificate lifecycle, and hardening
• Manage authentication and authorization infrastructure
• Own configuration management and automated provisioning of infrastructure
• Provide clear written incident communication and postmortem ownership

Candidates must provide accurate and complete information during recruitment. Limited use of AI tools to refine application materials is acceptable but candidates are responsible for their submissions. Applications may be processed using automated tools for evaluation, supporting but not replacing human decision-making. Candidates can opt out of automated evaluation by submitting applications directly via email.