Edit distance (Levenshtein): the 2D dynamic programming pattern.
Edit distance is the archetypal 2D string DP, powering spell-check, diff, and fuzzy matching. What interviewers watch for: naming the subproblem and the insert/delete/replace recurrence. Here is the answer.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Edit distance is the archetypal 2D string DP, powering spell-check, diff, and fuzzy matching. What interviewers watch for: naming the subproblem and the insert/delete/replace recurrence. Here is the answer.
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.
