Performance

Three hardware ideas that decide whether your low-latency code is fast or pretending to be: how the cache hierarchy works, why branch prediction can change runtime by 5×, and how false sharing makes lock-free code slower than mutexes.

A walk through Generational ZGC: coloured pointers, load and store barriers, the generational split landed in JDK 21, and how it hits sub-millisecond pauses on multi-TB heaps.