Senior Backend Engineer (Node.js) (Tesonet Global, UAB)

Job description:
Are you passionate about cybersecurity and ready to join a fast-growing company? At Surfshark, you'll be a crucial part of our mission to humanize digital security, specifically within our Scam Protection vertical.
In this role, you won't just be building side features, you will own the Node.js backends and detection pipelines that decide whether an email, SMS, or call is a scam. By managing the APIs and edge infrastructure, you'll reach a global audience and make cybersecurity accessible to everyone. Ready to make a difference and own the core of our scam detection technology? Apply now to join the Surfshark team!
Build cybersecurity products people use to dodge real scams, and invent the next ones;
Own the Email/SMS/Call Scam backends: APIs, pipelines, quality, cost, latency;
Design the automated email checker: background scanning, HTML/URL analysis, safe credential handling;
Maintain and evolve our Cloudflare Workers for routing, auth, and edge;
Collaborate autonomously across Browser Extensions, Mobile, Design, Infrastructure, Data Science, and QA;
Write maintainable, well-tested code that solves real problems.
Requirements:
Proven backend experience with Node.js (Express or similar)
Strong understanding of REST APIs and API design
Experience with MongoDB (or similar) in production
Git and code review in GitHub or GitLab
Docker (and comfort around how services actually run in production)
You operate what you ship: logging, metrics, alerts, debugging
You keep iterating when it's noisy
You use AI in your development workflow
Nice to have
Have shipped Cloudflare Workers (or another edge runtime)
Have put LLMs or classifiers into a pipeline and weighed evals, cost, latency, or privacy
Know email/SMS as a protocol (headers, SPF/DKIM, shorteners, sender reputation)
Have used queues (RabbitMQ), AWS/GCP, Google Web Risk, or ClickHouse / BigQuery
Company offers:
Growth and learning opportunities: time dedicated to learning, conferences, online learning platforms, and books for your professional development
Health and wellness: we want you to feel and be your best. That's why we offer various benefits, from online workouts and a physical coach to health insurance and regular mental health checks
Tools of your choice: choose the technical equipment and tools you need to do your best work
Community and celebrations: get ready for long-lasting traditions such as yearly workation, Friday get-togethers, various team buildings and company celebrations
Work-life balance: We encourage working in the office, with the possibility of up to two remote days per week. Plus, with our WFA policy, you can work from almost anywhere in the world
More days off: additional vacation days depending on your tenure
Premium Surfshark accounts: for you, your family, and friends