Coinbase Coding Interview Questions
28 Coinbase coding interview problems with full optimal solutions — 16 easy, 9 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Coinbase interviewer values, and a FAQ section.
Showing 9 problems of 28
- #17mediumfoundational
17. Top K Frequent Elements
Surface the K most-traded assets on an exchange — Coinbase uses this problem to test whether you reach for a heap over a naive sort when ranking trade volumes across thousands of instruments.
- #18mediumfoundational
18. Coin Change
Compute the fewest denominations to reach an exact value — Coinbase uses this DP classic to see how you model currency conversion and minimum-fee routing across crypto denominations.
- #19mediumfoundational
19. Merge Intervals
Collapse overlapping trading windows into consolidated ranges — Coinbase uses interval merging to evaluate how engineers reason about time-series events like order-book snapshots and candlestick aggregation.
- #20mediumfoundational
20. Min Stack
Track the minimum portfolio value at O(1) cost — Coinbase asks this to test whether you can maintain auxiliary state for instant low-watermark reads without rescanning the full price history.
- #21mediumfoundational
21. LRU Cache
Build a fixed-capacity account-data cache that evicts the least-recently-used entry — Coinbase uses this design question to measure whether you can combine a hash map and a doubly-linked list for O(1) reads and writes.
- #22mediumfoundational
22. Number of Islands
Count disconnected clusters in a grid — Coinbase maps this to partitioning liquidity pools or detecting isolated market segments that cannot route to a shared settlement layer.
- #25mediumfoundational
25. Longest Substring Without Repeating Characters
Find the longest run of unique trading-pair symbols in a sequence — Coinbase uses sliding-window problems to evaluate how you model streaming data with a shrinking-left-boundary technique common in real-time feed deduplication.
- #26mediumfoundational
26. K Closest Points to Origin
Retrieve the K accounts with the smallest distance from a reference price level — Coinbase uses this heap problem to test real-time top-K selection, the engine behind their order-proximity ranking in the matching engine.
- #27mediumfoundational
27. Network Delay Time
Find the worst-case latency before a broadcast reaches every node — Coinbase uses Dijkstra problems to evaluate how engineers reason about minimum-cost routing across crypto-network relay nodes and cross-chain bridging hops.
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