OpenAI
6 questions · Coding · System design · Behavioral
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 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 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.
Design a system to run and evaluate model prompts at scale.
System designApproachJob queue, caching identical calls, cost tracking, and result storage/eval.
They look forPractical infra thinking around LLM workloads.
Describe a project you are most proud of and your specific contribution.
BehavioralApproachAnchor to measurable impact; be crisp about what YOU did vs. the team, and the trade-offs you made.
They look forOwnership, impact, and honest self-attribution.
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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