Senior Site Reliability Engineer - VPN Service | NordVPN

Full Time

hybrid

Infrastructure

Vilnius / Kaunas

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 operates a globally distributed VPN and DNS infrastructure serving millions of users. Your responsibility is the service itself - deploying, managing, and improving VPN nodes worldwide while ensuring every client connection is fast, stable, and secure.

You'll work closely with application teams to guarantee smooth client connectivity end to end. Quality and reliability are the job.

Main Responsibilities

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 — kernel tuning, flamechart analysis, profiling

Manage security posture — firewalls, PKI, certificate lifecycle, hardening

Manage authentication and authorization infrastructure

Own configuration management and automated provisioning of infrastructure

Clear written incident communication and postmortem ownership

Core Requirements

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, refactors, etc

Raises engineering quality through standards, design reviews, knowledge sharing and mentorship

Balances reliability, security and delivery speed with strong operational judgment

Advanced networking - VPN protocols, tunneling, routing, DNS

Linux at depth - kernel internals, tuning, module management

Firewall management

Performance analysis - flamecharts, profiling, bottleneck identification

OSI model fluency - L2 through L7, TCP/IP stack, SSL/TLS

Security fundamentals - PKI, certificate management, hardening

Authentication and authorization - RADIUS, access control

Configuration management and automated deployments

Load balancing and failover for distributed services

Docker

Bonus Points For

Python programming

C, Rust, or Go - for lower-level service and performance work

Observability knowledge - monitoring, metrics, logging for VPN services

On-demand bare-metal/hardware provisioning

eBPF, strace, and advanced debugging/tracing tools

Virtualization - KVM, MicroVM

Kubernetes networking

Interest in AI tooling - Claude Code, agentic engineering, LLM integrations in engineering workflows

Tools You Will Use

Linux kernel and networking stack

SaltStack

Consul

Firewall - nftables

DNS - BIND, dnsdist, Unbound

FreeRADIUS

Vault and PKI infrastructure

MySQL (Percona), Redis

Docker

iPXE

Salary Range

Gross Salary 5800-7400 EUR/Month

Perks we offer

Our global mission fuels our drive. But when you need that extra push - here’s a list of things to look forward to.

Apply for this job

Infrastructure

Vilnius / Kaunas

Full name

Phone number

Link to profile

Your city

Which location is closest to you?

Resume (optional)

Nord Security is committed to building an inclusive workplace with a diversity of backgrounds. We welcome applications from people of all ages, gender identities, sexual orientations, racial identities, ethnicities, religious beliefs, and disability statuses. To reduce the chance of unconscious bias, you may submit your CV without a photograph or other redundant information like age or marital status.

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. .

By filling in this form you confirm that you have read and understood the Privacy Notice for Recruitment Candidates.

I consent that Nord Security can contact me about future job opportunities for up to 3 years.

Our values

Our values are rooted in the actions of our people. They describe how we solve problems, make decisions, and ultimately - reach our goals as a team.