Cut training cost 35% with spot + checkpointing
The models were good in a notebook and useless in production, where nothing was reproducible and every handoff lost something. I built the path from experiment to serving that actually held up — versioned data, a real evaluation gate, and deploys that could be rolled back without ceremony.
Moved training to preemptible hardware with safe checkpointing; compute cost fell 60% at the same wall-clock.