Find near-duplicate documents in a 1TB corpus without comparing every pair.
All-pairs comparison is O(n^2) and dies long before 1TB. The senior move is MinHash plus LSH: hash documents so only likely-similar pairs ever land in the same bucket, then verify just those.
Updated Aug 2026 · Grounded in real Forward Deployed Engineer interview loops and written to a senior-engineer editorial bar.
All-pairs comparison is O(n^2) and dies long before 1TB. The senior move is MinHash plus LSH: hash documents so only likely-similar pairs ever land in the same bucket, then verify just those.
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.
