Explain backtracking and use it to generate all permutations / subsets / combinations.
Backtracking underlies permutations, subsets, N-queens, and constraint problems. Interviewers look for the choose/explore/un-choose template plus pruning, and knowing exactly which knob distinguishes permutations from combinations.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Backtracking underlies permutations, subsets, N-queens, and constraint problems. Interviewers look for the choose/explore/un-choose template plus pruning, and knowing exactly which knob distinguishes permutations from combinations.
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.
