core practice · coding problem
Checkpoint must include optimizer state
You save weights only (no optimizer state) at step 10k, resume training. What goes wrong with Adam momentum estimates?
The mechanism
A checkpoint saves the weights and optimizer state so you can resume after a crash. Save often enough that any single failure costs less than an hour. Keep the most recent few and your best-eval-score one separately.
Expected evidence
Optimizer moments reset — loss spike / different trajectory; effective warmup replay.
Try this drill in the practice workspace →
Hints when you need them
- Adam stores m and v per parameter.
- Resume needs weights + optimizer + step + RNG if exact replay.