Find duplicate files in a directory tree by content: size prefilter, then hashing.
A grounded systems-coding screen: locate files with identical content across a tree. The naive all-pairs hash wastes work. The signal is the size prefilter plus a cheap-hash gate ahead of the full hash. Here is the layered approach.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
A grounded systems-coding screen: locate files with identical content across a tree. The naive all-pairs hash wastes work. The signal is the size prefilter plus a cheap-hash gate ahead of the full hash. Here is the layered approach.
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.
