Kth Smallest Element in a BST (in-order traversal).
This one rewards knowing that an in-order walk of a BST produces sorted order. The signal is halting at the kth element instead of walking the entire tree.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
This one rewards knowing that an in-order walk of a BST produces sorted order. The signal is halting at the kth element instead of walking the entire tree.
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.
