The compiler accepting your code is not evidence it is correct

Every language has places where it hands you the pen and stops checking. In Swift it is @unchecked Sendable, force unwraps, unsafe pointers. In Kotlin it is !!, @Suppress, unchecked casts. These are not safety features. They are liability waivers, and the code is only as safe as the promise behind them.

The senior habit is knowing exactly where those places are, because they are the first places to check in review. When you see a manual trust me annotation, the only question that matters is: where is the mechanism that makes the promise true? A lock, a queue, an actor, an invariant. If the answer is nowhere, you have found the 3am crash before it happens.

This transfers directly to interviews: when handed code that looks innocent, the senior move is to find where the guarantees were switched off. That one question, this claims to be safe, what enforces it, is worth more than a recitation of every concurrency primitive in the language.