Someone trained a language model on an $8 microcontroller, backprop hand-written in C.

Carloscodix/qapla hit the HN front page at 41 points one day after creation, 43 stars, Apache 2.0. The explicit claim is training, not inference: the complete loop with backpropagation by hand on an ESP32-S3. A curiosity, not a product. But it's a clean floor estimate for training hardware at a moment when the dominant number in every AI conversation is a gigawatt interconnection queue, and the hand-written C makes it genuinely readable as a teaching artifact.