Senior Site Reliability Engineer - VPN Service | NordVPN

Nord Security develops advanced cybersecurity tools such as Threat Protection Pro and the NordLynx protocol, offering the fastest VPN globally with a focus on privacy, security, and user control.

• 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
• Expertise in Linux kernel internals, tuning, and module management
• Firewall management experience
• Performance analysis skills involving flamecharts, profiling, and bottleneck identification
• OSI model fluency (L2 through L7), including TCP/IP stack and SSL/TLS
• Security fundamentals including PKI, certificate management, and hardening
• Authentication and authorization expertise, including RADIUS and access control
• Configuration management and automated deployments
• Load balancing and failover for distributed services
• Experience with Docker

Nice to have:

• Programming skills in Python
• Experience with 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
• Use of eBPF, strace, and advanced debugging/tracing tools
• Virtualization experience with KVM and MicroVM
• Kubernetes networking knowledge
• Interest in AI tooling, including Claude Code, agentic engineering, and LLM integrations in 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 allowed, but candidates remain responsible for the authenticity of submissions. Applications may be processed using automated tools for evaluation, supporting but not replacing human decision-making. Candidates may contact the company for data privacy concerns or opt out of automated evaluation by direct application submission.