Zalando Developed an In‑Process Client‑Side Load Balancer Handling One Million Requests per Second

Zalando engineers created a client‑side load balancer that runs within the application process. The balancer is capable of handling one million requests per second. It distributes traffic across internal services without external proxies. The design reduces latency and simplifies deployment architecture. Implementation details were shared in a recent technical article. The solution leverages in‑process routing logic and health checks. Zalando reports improved throughput and resource efficiency. The approach may influence other high‑scale web services seeking similar performance.