Nano-vLLM: How a vLLM-style inference engine works
by yz-yu on 2/2/2026, 12:52:35 PM
https://neutree.ai/blog/nano-vllm-part-1
Comments
by: jbarrow
The whole thing feels AI written, generated from the codebase.*<p>*this is incorrect per the author’s response, my apologies.<p>For instance, it goes into (nano)vLLM internals and doesn’t mention PagedAttention once (one of the core ideas that vLLM is based on)[1].<p>Also mentions that Part 2 will cover dense vs MoE’s, which is weird because nanovllm hardcodes a dense Qwen3 into the source.<p>Here are better (imo) explainers about how vLLM works:<p>- <a href="https://hamzaelshafie.bearblog.dev/paged-attention-from-first-principles-a-view-inside-vllm/" rel="nofollow">https://hamzaelshafie.bearblog.dev/paged-attention-from-firs...</a><p>- <a href="https://www.aleksagordic.com/blog/vllm" rel="nofollow">https://www.aleksagordic.com/blog/vllm</a><p>- <a href="https://huggingface.co/blog/continuous_batching" rel="nofollow">https://huggingface.co/blog/continuous_batching</a><p>Aleksa’s blog is a bit in the weeds for my taste but it’s really worth working through.<p>A lot of the magic of vLLM happens in the PagedAttention kernels, which are really succinctly implanted in nanovllm. And the codebase is great and readable by itself!<p>—<p>1. <a href="https://arxiv.org/abs/2309.06180" rel="nofollow">https://arxiv.org/abs/2309.06180</a>
2/2/2026, 2:18:19 PM
by: yz-yu
Since HN only allows one link per submission, dropping Part 2 here.<p><a href="https://www.neutree.ai/blog/nano-vllm-part-2" rel="nofollow">https://www.neutree.ai/blog/nano-vllm-part-2</a>
2/2/2026, 3:43:24 PM