From TypeScript to Go: How We Cut Infra Cost 26x Without Rewriting Everything

“Rewrite it in Go” is easy advice to give and dangerous advice to follow. Full rewrites often burn months, break product velocity, and recreate bugs that were already solved. But when a service is CPU-heavy, latency-sensitive, and running at growing scale, the implementation language can become part of the architecture. This talk shares how selected production workloads moved from TypeScript to Go in a real-time attribution platform, cutting infrastructure cost by 26x without stopping product work or rewriting the entire system. We will cover how we chose migration candidates, separated hot paths from stable product code, designed compatibility boundaries, benchmarked carefully, and rolled out on Kubernetes with observability and rollback paths. The goal is not a language war. It is a decision framework for developers considering performance-driven migrations while keeping users and product teams moving.