Implement batch normalization (forward pass, train and inference) from scratch.
Coding BatchNorm verifies you know the train/inference difference, the part everyone forgets. Interviewers look for normalizing over the batch with running stats kept for inference. The implementation follows.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Coding BatchNorm verifies you know the train/inference difference, the part everyone forgets. Interviewers look for normalizing over the batch with running stats kept for inference. The implementation follows.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
