Microsoft
7 questions · Coding · System design · Behavioral
Find two numbers in an array that sum to a target and return their indices.
CodingApproachOne pass with a hash map of value → index; for each x, check whether target − x was already seen.
They look forWhether you move from the brute-force O(n²) to a clean O(n) hash-map solution and reason about edge cases.
Reverse a singly linked list in place.
CodingApproachIterate with three pointers (prev, curr, next), rewiring links; discuss the recursive variant and its stack cost.
They look forPointer manipulation, in-place mutation, and clarity under a deceptively simple task.
Given course prerequisites, decide whether all courses can be finished.
CodingApproachBuild a directed graph and run topological sort (Kahn/BFS or DFS cycle detection).
They look forRecognizing a cycle-detection problem behind a word problem.
Design a rate limiter for a public API.
System designApproachCompare token bucket vs. sliding window, where state lives (per-node vs. Redis), and behavior under bursts.
They look forAlgorithm choice, distributed state, and failure/consistency trade-offs.
Design a search autocomplete / typeahead service.
System designApproachTrie or prefix index, top-k ranking, caching, and updating suggestions from live traffic.
They look forLatency budget, data-structure choice, and freshness vs. cost.
Tell me about a time you disagreed with a teammate or manager.
BehavioralApproachUse STAR: the situation, your reasoning, how you disagreed respectfully and reached a decision, and the result.
They look forCommunication, judgment, and whether you can disagree-and-commit without drama.
Tell me about a time you failed and what you changed afterward.
BehavioralApproachPick a real failure, own it without blaming others, and show the concrete lesson you applied later.
They look forSelf-awareness, accountability, and growth.
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