Aman Mehtar
Writing
Notes on building products, software craft, and shipping in public.
2026
Turning a Locked JioFiber Gateway into a Wireless Repeater (and the Error Code that Fooled an AI)
My agent gained root on a spare JioFiber JCOW411, spent hours in the weeds of closed Broadcom drivers, and concluded a wireless repeater was 'impossible on this hardware'. It wasn't impossible — here is how Broadcom WET mode and a misread error code cracked it wide open.
Turning Qwen into a price predictor on an 8GB laptop GPU
A text-only Qwen3.5-2B, 4-bit LoRA and a nine-quantile regression head took Amazon product pricing from a 68.83 SMAPE baseline to 44.11 in two laptop-sized epochs.
214M parameters, 36 lost GPU-hours, and the day my agent outsmarted itself
Phase 1 of miniLLM-214M went perfectly on Kaggle's free T4s. Phase 2 failed for reasons that had nothing to do with deep learning — and the model driving my coding agent is the one that failed.
Training a fill-in-the-middle code model for $16
113M parameters, 1.4B tokens of 2024-or-newer code, 4.6 hours on four L4s — and two headline results that shrank when I measured them properly.
August, wrapped
154 commits, 15 new repos, 3 models trained from scratch, and one number I'm not proud of.
Chess two ways: a world model vs a board you can see
One model reads move text and builds the board itself. The other gets the board handed to it. Same domain, opposite bets — and the numbers say something uncomfortable.
A 94M chess model that built a board it was never shown
Character-level SAN, no board in the input, and a linear probe that reads the position out of the activations at 85.6%.
Training a 101M language model on a laptop GPU
12 hours, 8GB of VRAM, 1.2B tokens of FineWeb-Edu, and a measured 2.7x win from swapping the optimizer.
Hello, world
First post — how writing works on this site.