Hareesh Gali
Side projects

Side projects

07

An elephant through a straw

A 284B mixture-of-experts model, a 24GB 4090, and one NVMe drive. For an evening it ran at 12.9 tok/s, which turned out to be the model writing the word "dekameters" 108 times because loops are cache-friendly. Also: a 2-bit copy of 11,008 experts, a net that guesses the router two layers early, and five dead ends with the numbers that killed them.

MoENVMe offloadingquantizationCUDA graphs
2026
06

Qwen plays Smash

A 1.7B LLM in Melee's per-frame control loop. 30ms CUDA-graph scoring, an Nsight trace of where the time really goes, 6,144 imagined futures per decision, a critic that loses to a single constant, and a baseline comparison the LLM does not win. With a scrubbable match player.

LLM agentsCUDA graphsworld modelsMelee
2026
05

One launch per token

A from-scratch fused decode megakernel that runs a whole transformer step in one CUDA-graph launch and beats vLLM's batch-1 latency on a 4090, for a dense model and a 64-expert MoE. Plus two H100s and an honest negative result.

GPU kernelsTritonCUDA graphsMoE
2026
04

Don't read the haystack

Triton flash-decode kernels at 94% of my 4090's memory bandwidth, then 16x past them with page-sparse attention, because the frontier of inference is refusing to read.

GPU kernelsTritonsparse attention
2026
03

Why the answer is D

I inserted a wrong answer into a reasoning model's prompt and probed its residual stream to find out when it actually decides. Spoiler: sometimes before it starts "thinking."

interpretabilitychain-of-thoughtlinear probes
2026
02

A dial for a language model's mind

A single direction added to an LLM's activations dials a behavior up and down like a knob. Extracted on one 4090, running live in your browser. Drag the slider.

interpretabilityactivation steeringinteractive
2026
01

A stupid amount of work for a date

Rebuilding the lantern scene from Tangled as a walkable 3D world you can stand inside. Gaussian splats, a 480p ceiling, and one genuinely cursed NCCL error.

3D Gaussian splatsHunyuanWorldH100
2026