LLM Training: The End-to-End Flow

What each step of an LLM training iteration computes, what it costs in memory and arithmetic, and where the loop stalls on real hardware.

August 10, 2026 · 19 min · Sandeep Kumar

The KV Cache: Sizing It, and the Attention Variants That Shrink It

What the KV cache costs per token, and how MQA, GQA and MLA rewrite attention to make that number smaller.

August 12, 2026 · 10 min · Sandeep Kumar

Tiling and Collective Operations

The two data-movement primitives behind training performance: tiling inside a device, collectives between devices.

August 12, 2026 · 17 min · Sandeep Kumar

PyTorch Distributed Training Internals

The mechanism behind step 5 of the training loop: bucketed gradient all-reduce triggered from autograd hooks, what NCCL does with it, and how to diagnose the result.

August 12, 2026 · 13 min · Sandeep Kumar

PagedAttention

How PagedAttention uses virtual-memory-style KV-cache paging to reduce fragmentation and increase LLM serving throughput.

March 3, 2026 · 5 min · Sandeep Kumar

FlashAttention: Exact Attention Without Materialization

How FlashAttention computes exact attention without materializing quadratic score and probability matrices in GPU memory.

March 8, 2026 · 9 min · Sandeep Kumar

Neural Network Quantization

What quantization actually changes in a network, which parts of a transformer break first, and which techniques repair them.

August 12, 2026 · 13 min · Sandeep Kumar

The Evolution of FlashAttention: From Ampere to Blackwell

How successive FlashAttention implementations respond to the bottleneck exposed by each new GPU generation.

August 7, 2026 · 7 min · Sandeep Kumar

FlashInfer: A Customizable Attention Engine for LLM Serving

FlashInfer treats LLM attention as a serving systems problem spanning data layout, kernel generation, and runtime scheduling.

August 7, 2026 · 12 min · Sandeep Kumar