Elastic Coding Interview Questions
25 Elastic coding interview problems with full optimal solutions — 8 easy, 12 medium, 5 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Elastic interviewer values, and a FAQ section.
Showing 3 problems of 25
- #1easyvery frequently asked
1. Two Sum
Find two indices in an array whose values sum to a target. At Elastic, this tests your instinct for trading memory for speed — the same hash-map lookup pattern powers fast term lookups inside Elasticsearch's inverted index.
- #70easysometimes asked
70. Climbing Stairs
Count the distinct ways to climb n stairs taking 1 or 2 steps at a time. Elastic uses this as an entry-level dynamic programming probe — if you can articulate why the recurrence is Fibonacci and spot the O(1) space optimization, you signal that you think about caching and state compression the way Elasticsearch's query cache does.
- #141easysometimes asked
141. Linked List Cycle
Detect whether a linked list contains a cycle. Elastic uses Floyd's tortoise-and-hare algorithm here as a proxy for distributed-systems intuition — detecting liveness vs. livelock in a cluster follows the same principle of needing two probes at different rates to distinguish 'still making progress' from 'spinning in a loop'.