Senior Site Reliability Engineer - Traffic Engineering | NordVPN at Nord Security

The world’s most advanced VPN, and a whole lot more.   If you’re a curious problem-solver who carves their own path, join the team behind Threat Protection Pro, the NordLynx protocol, and the fastest VPN on the planet—tools that put privacy, security, and control back in people’s hands. Your impact? Helping millions take back control of their online security, privacy, and data. NordVPN serves millions of users through a global edge network. Your number one responsibility is content accessibility - making sure traffic reaches users reliably, quickly, and securely, everywhere in the world.   You'll work at the intersection of networking, load balancing, and traffic shaping. When something is slow, unreachable, or misbehaving at the protocol level, you're the person who finds out why and fixes it. Main Responsibilities • Ensure content accessibility across a globally distributed edge infrastructure • Design, operate, and improve load balancing and traffic shaping systems at scale • Troubleshoot connection, latency, and accessibility issues end to end • Own HTTP traffic flow - from client to edge to origin and back • Investigate and resolve website and service reachability problems • Work across protocol layers to diagnose issues at the right depth Core Requirements • Load balancing and traffic shaping - architecture, algorithms, health checking, failover • NGINX and/or HAProxy - configuration, tuning, debugging in high-traffic environments • Networking fundamentals - DNS, routing, firewall, packet capture and analysis • OSI model fluency - comfortable working across L3–L7, TCP internals, SSL/TLS handshake and termination • SaltStack • Linux administration • Python programming - automation, tooling, scripting • Troubleshooting network and application-layer issues in production at scale • Observability knowledge - metrics, logging, and monitoring for traffic systems • Docker knowledge - full lifecycle and dependency management with advanced networking Bonus Points For • Advanced networking - anycast, BGP, traffic engineering at the network layer • Deep understanding of the HTTP protocol - HTTP/1.1, HTTP/2, HTTP/3, WebSocket, connection lifecycle • Proxy protocols - PROXY protocol v1/v2, reverse proxy patterns, header propagation Salary Range • Gross Salary 5800-7400 EUR/Month What We Offer Innovate with industry leaders Work alongside global experts to build world-leading cybersecurity tools, impacting millions of users around the world. Learn & grow Boost your skills via our extensive training programs (online and offline) & other resources. Benefit from mentorship and career-switch opportunities to grow within the company.  Work in a next-gen Cyber City office Thrive in our bustling office, featuring ergonomic workspaces, modern meeting rooms, engaging events, and specialty coffee to fuel your day. Hybrid work Enjoy the flexibility with 3 office days and working from home for the remaining 2. Work from anywhere Recharge with a change of scenery – choose work from any location when you feel a need to power your creativity and drive.   Physical well-being Boost your health with free-of-charge 24/7 gym access, onsite and online workouts, and consultations led by in-house Physical Well-Being experts.  Mental & emotional health Nurture your mind with free psychologist consultations, dedicated mental health events, and premium access to top-rated wellness apps like Calm, Headspace, and Mindletic. Premium healthcare Receive private health insurance giving you peace of mind for your health needs. Extra days off Enjoy additional vacation days off as you grow with us. Plus, get extra days for sick leave, special occasions, or parenting needs.   Joyful moments – special treats Celebrate life’s big moments with special gifts from us on your birthday, anniversary, and other major events, such as weddings or the arrival of a new family member.   Company events & team-building Experience iconic Nord Security celebrations, team-buildings, and knowledge-sharing events, nurturing bonds that fuel our success. Workation Embark on a legendary company getaway abroad, filled with exciting activities, live concerts, engaging workshops, and epic time together. Kindly refer to our Privacy Notice for Recruitment Candidates for comprehensive information regarding our data handling procedures throughout recruitment processes: [Upgrade to PRO to see link] We expect all candidates to provide accurate and complete information during the recruitment process. While limited use of AI tools to refine application materials is acceptable, candidates remain fully responsible for ensuring that their submissions reflect their own qualifications, skills, and experience. Any failure to do so may negatively affect participation in the recruitment process. If broader AI assistance is allowed for a particular role or stage, we’ll let you know in advance. By submitting your application, you acknowledge that it may be processed using automated tools for evaluation purposes. As part of our recruitment process, we may use an AI-based application review tool to help assess applications based on skills and experience relevant to the role. This technology is used to support - not replace - human decision-making, and every application is ultimately reviewed by a recruiter. If you would like more information about how AI is used in this process or wish to exercise your rights under applicable data privacy laws, please contact us at [Upgrade to PRO to see contact]. Should you prefer to opt out of the automated evaluation, please submit your application directly to [Upgrade to PRO to see contact].