Case Study: DoubleVerify achieves 90% cost reduction and billions-per-day scalability with HAProxy Enterprise

How DoubleVerify Transitioned from F5 to HAProxy Enterprise

DoubleVerify, a global ad-verification platform that monitors impression quality and detects fraud, faced rapidly rising costs and operational limits from legacy hardware load balancers (Citrix/F5). The company was processing hundreds of thousands of requests per second and needed a scalable, configurable, and observable solution that would integrate with CI/CD and run on commodity hardware—so they moved to HAProxy, specifically HAProxy Enterprise, to replace their expensive VIPRION appliances.

HAProxy Enterprise was deployed on horizontally scaled commodity servers and tuned with multi-process/CPU‑mapping, Keep‑Alive, and the Runtime API, with configurations automated via tools like Ansible. As a result, HAProxy enabled real-time observability, on‑the‑fly reconfiguration, and redundancy while cutting load‑balancing costs to about one‑tenth of previous spend and supporting over 5,000,000,000 daily requests (≈595,000/sec peak).

DoubleVerify

Wally Barnes

Senior Systems Engineer