How does Bayesian optimization tune hyperparameters, and when is it better than grid/random search?

Grid and random search ignore past results. Bayesian optimization learns from them, and the signal is whether you can explain the surrogate plus acquisition loop and name the exact condition where the sample-efficiency is worth it. Here is the answer.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.