Bloomberg
5 questions · Coding · System design
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.
Find the length of the longest substring without repeating characters.
CodingApproachSliding window with a set/last-seen map; advance the right edge, shrink the left on a repeat.
They look forTwo-pointer/sliding-window fluency and off-by-one care.
Design and implement an LRU cache with O(1) get and put.
CodingApproachCombine a hash map with a doubly linked list; move touched nodes to the front, evict from the tail.
They look forComposing data structures to hit tight time bounds and getting the eviction bookkeeping right.
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.
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.
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