The document discusses how modern hardware has become more complex with multi-core, multi-socket CPUs and deep cache hierarchies. This complexity introduces latency and performance issues for software. The author describes their service that processes millions of requests per second spending a large amount of time on garbage collection, context switching, and CPU stalls. They developed a tool called Tesson that analyzes hardware topology and shards containerized applications across CPU cores, pinning linked components closer together to improve locality and performance. Tesson integrates with a local load balancer to distribute workloads efficiently utilizing the system resources.