Episode 42 of The Web Development Podcast digs into a surprising performance regression: Webpack builds running 40% slower on Apple's new M4 Macs compared to M1 and M2 machines. Lucas and Luna trace the root cause to a change in the ARM microarchitecture's memory prefetcher behavior, which breaks assumptions in the terser-webpack-plugin's parallel worker hot-path. They walk through the Node.js worker_threads internals, the specific CPU instruction stalls, and the two-line fix using worker-data serialization flags that restores parity. The episode also covers why this issue silently affects CI runners and how to detect it with a simple benchmark script. A concrete deep dive for any web developer using Webpack on Apple Silicon machines.

#Webpack #M4Mac #AppleSilicon #Performance #ARM #NodeJS #TerserPlugin #WebDevelopment #Frontend #BuildTools #CI #CPUArchitecture #MemoryPrefetcher #ParallelWorkers #Benchmarking #Technology #FexingoBusiness #BusinessPodcast

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