Explain HashMap Resizing Without Long Pauses

Describe the internal mechanics of a hash map. Include how keys get assigned to buckets, the strategy used for collisions, and the conditions that trigger a resize.

Follow-up: a resize normally means allocating a bigger bucket array and rehashing all current entries into it, which can cause a visible latency spike. Propose a method to bound or smooth that latency without giving up expected constant-time lookups and inserts.

Overview: This question assesses knowledge of hash map internals—key-to-bucket mapping, collision resolution, and the timing and reasons for resizing—and tests skill in data structures and performance engineering in the Software Engineering Fundamentals area.