Core answer
Start here. This is the direct spoken answer to practice first.
Why this question matters
Estimates are often wrong. The interview signal is whether the candidate notices early, communicates clearly, and adjusts responsibly.
I underestimated a feature because I treated it like a simple CRUD screen, but the real work included permissions, audit history, validation, and migration of existing data. Once I realized the scope was larger, I did not wait until the deadline. I wrote down what was discovered, what remained, and which parts were required for a safe release. Then I reset expectations with the lead and product owner.