Minimum Window Substring: which companies ask it and how to practise

Minimum Window Substring is a Hard problem that 36 companies are reported to ask. This page shows who, how often and how recently, what the question tests, and how to practise it out loud with an interviewer who asks follow-ups. We link to the original problem statement instead of copying it.

Which companies ask Minimum Window Substring?

Public company lists attribute Minimum Window Substring, a Hard problem, to 36 companies. The most frequent askers are Wissen Technology, Lyft and Snap. 8 reports are from the last six months. It mainly tests hash table, string and sliding window. Use this as a practice guide, not a promise.

Practise this kind of question aloud

Who asks Minimum Window Substring

36 companies appear in the public lists for this question. By how often each is reported: Wissen Technology (very often), Lyft (very often), Snap (very often), SoFi (very often), Apollo.io (very often), Snowflake (very often), Harness (very often), DP world (very often), thoughtspot (very often) and Zeta (very often), and 26 more. 8 of them were reported in the last six months, Lyft, Meta and Amazon among them.

These are candidate reports collected in public lists, not statements from the companies. They are a good guide to what to practise and a poor guide to what you will be asked: interviewers change questions, and the same company asks different questions by team and level. Last reviewed 25 October 2026.

What Minimum Window Substring tests

It is rated Hard, so a correct brute force with a clear path to the better idea is a good result; interviewers watch how you reason when the answer is not obvious and how you use their hints.

A hash table trades memory for speed: remembering what you have seen turns a repeated search into a lookup. Interviewers want you to say that trade-off and the cost of collisions or a bad key.

String problems test careful index handling and knowing which characters you may assume. Say out loud whether the input is ASCII, whether case matters, and what an empty string should return.

A sliding window keeps a running answer for a moving range. Say what makes the window valid and when you shrink it.

How to practise it

Do not just solve it silently. In a real interview you explain the approach before you code, write while you talk, and defend the solution to follow-ups. Set a timer, say the brute force and its cost first, then improve it, and finish by stating the time and space complexity and two edge cases you tested.

On giveinterview you can take this kind of question as a spoken interview: the AI interviewer opens with the problem, watches you code, asks cross-questions and ends with a scorecard. Your first 3 single-question interviews are free for life, every interview report is free, and a new account also gets 6 welcome credits.

Read the original statement here: https://leetcode.com/problems/minimum-window-substring/ (opens the publisher's page). The statement is theirs; we do not reproduce it.

Questions to practise next

If you can solve Minimum Window Substring, try these next, chosen because they share its main topic and many of the same companies: Two Sum (Easy), LRU Cache (Medium), Longest Substring Without Repeating Characters (Medium), Group Anagrams (Medium), Top K Frequent Elements (Medium) and Subarray Sum Equals K (Medium). Each has its own page in the questions list.

Frequently asked questions

Is Minimum Window Substring asked at Amazon?

Amazon appears in the public lists for Minimum Window Substring, reported often. Treat that as a reason to practise it, not a promise you will be asked it.

How hard is Minimum Window Substring?