Machine Learning System Design Interview, issue 13, Nov 30, 2025
The Flat Loss Trap
Senior ML Engineer interview, and the interviewer asks:
“You just implemented a complex Transformer from a new paper. The code runs without errors. The training loop executes. But the loss curve is completely flat. What is your first move?”
Why tuning a broken model is pointless - and how the single-batch overfit saves you in every deep learning interview.
The full answer, with the mechanism and the arithmetic, is for paid subscribers on Substack.