Redis Coding Interview Questions
25 Redis 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 Redis interviewer values, and a FAQ section.
Showing 1 problem of 25
- #20mediumsometimes
20. Subarray Sum Equals K
Subarray Sum Equals K counts how many contiguous slices of an integer array sum to exactly k — and because values can be negative, sliding windows break and the prefix-sum hashmap becomes the only linear path. Redis candidates report it as a favorite medium because the core identity, sum(i..j) = prefix[j] - prefix[i-1], is the same cumulative-counter thinking an in-memory data store applies to range queries over append-only streams.