Pretraining against the clock on one Trainium2 chip
AWS Trainium Frontier Competition. Train a language model from scratch in 30 minutes of wall-clock on a single Trainium2 chip, scored on held-out bits per byte. I treated it as a measurement problem: profile first, change one thing, climb a validation ladder before paying for a full run, and pre-register the rule that decides.
Official val bpb 0.947182, down from 1.1728 over 16 submissions