Hi, this is Xuewen. I’m documenting my learning notes in this blog since 2026.

Parallelism for LLM training, with numbers you can check by hand

Data, ZeRO, tensor, sequence, context, pipeline and expert parallelism, each worked through with a tiny example: what gets split, what moves between GPUs, and when to use which.

November 1, 2026 · 33 min · 6947 words · Xuewen Yang