Senior Backend Engineer — AdTech Edge & High-Load Systems

Sigma Software; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

Sigma Software is seeking a senior back-end engineer to own the Vast Gateway service, a high-throughput edge proxy built on Cloudflare Workers, handling millions of requests daily in the video ad flow.

You will design scalable back-end solutions for low-latency, highly available systems, integrate with VAST/VPAID workflows, monitor performance, and collaborate with distributed teams to evolve the platform architecture.

Qualifications

• 5+ years of commercial back-end development experience.
• Strong expertise in server-side JavaScript or other back-end technologies.
• Commercial experience in AdTech environments.
• Proven experience supporting production systems in high-load environments.
• Strong understanding of debugging, monitoring, hotfixing, and zero-downtime deployments.
• Solid knowledge of HTTP protocols, web fundamentals, HTML, and tracking pixels.
• Experience building scalable and highly available distributed systems.
• Strong analytical and problem-solving skills.
• Ability to independently own services and drive technical improvements.
• Upper-Intermediate English level or higher.
• Strong communication and collaboration skills in distributed teams.
• Experience with VAST protocol.
• Hands-on experience with Cloudflare Workers.
• Experience with VPAID creatives.
• Background in video advertising technologies.
• Experience with high-load distributed systems.
• Performance optimization expertise.
• Experience with edge-computing architectures.

Responsibilities

• Take end-to-end ownership of the Vast Gateway service.
• Maintain, develop, and extend platform functionality.
• Design and implement scalable back-end solutions for high-load environments.
• Support onboarding of new clients, including integrations, monitoring setup, troubleshooting, and optimization.
• Build custom features and integrations based on Customer requirements.
• Monitor system performance and proactively identify optimization opportunities.
• Ensure service reliability, availability, and low-latency performance.
• Participate in release planning, deployments, and production support activities.
• Improve observability through monitoring, alerting, and operational tooling.
• Collaborate with Product and engineering stakeholders to evolve platform architecture.

Skills

Back-end development

JavaScript

Node.js

Cloudflare Workers

AdTech

Distributed systems

High load

English

Tools

Cloudflare Workers

Monitoring tools

Job description

Sigma Software is seeking a senior back-end engineer to own the Vast Gateway service, a high-throughput edge proxy built on Cloudflare Workers, handling millions of requests daily in the video ad flow.

You will design scalable back-end solutions for low-latency, highly available systems, integrate with VAST/VPAID workflows, monitor performance, and collaborate with distributed teams to evolve the platform architecture.