Senior Backend Engineer (AdTech)

Location: Remote, Poland; Warsaw, Masovian Voivodeship

Company

Cybersecurity-focused company developing solutions that protect organizations, users, and digital ecosystems from online threats. The project is Vast Gateway, a high-throughput edge proxy built on Cloudflare Workers for video advertising delivery.

What you will do

• Take end-to-end ownership of the Vast Gateway service and extend its functionality.
• Design and implement scalable backend solutions for high-load environments.
• Support client onboarding through integrations, monitoring setup, troubleshooting, and optimization.
• Build custom features and integrations based on customer requirements.
• Monitor performance, improve observability, and identify optimization opportunities.
• Participate in release planning, deployments, production support, and platform architecture evolution.

Requirements

• 5+ years of commercial backend development experience.
• Strong expertise in server-side JavaScript or other backend technologies.
• Commercial experience in AdTech and production systems in high-load environments.
• Experience with debugging, monitoring, hotfixing, and zero-downtime deployments.
• Knowledge of HTTP protocols, web fundamentals, HTML, and tracking pixels.
• Experience building scalable, highly available distributed systems.
• Strong analytical, problem-solving, communication, and collaboration skills.
• Ability to independently own services and drive technical improvements in distributed teams.
• Upper-Intermediate English level or higher.

Nice to have

• Experience with the VAST protocol, Cloudflare Workers, VPAID creatives, or video advertising technologies.
• Background in high-load distributed systems and performance optimization.
• Experience with edge-computing architectures.

Culture & Benefits

• Full-time role with autonomous ownership of a high-responsibility service.
• Data-driven, analytical, proactive, and detail-oriented working style.
• Focus on reliability, quality, troubleshooting, and continuous improvement.
• Remote work arrangement in Poland.