Microsoft Interview Questions
Reconstructed from 134 verified candidate reports across 39 questions. Oct 2025 – Oct 2026.
This page is a live view of every Microsoft interview question AceOffer has indexed — pulled from candidate reports, not invented from job descriptions or one founder’s memory. Every question shows how many times it’s been reported and when it was last seen. The catalog gets a refresh pass every month.
AceOffer is not affiliated with, endorsed by, or sponsored by Microsoft. Questions are reconstructed from interview experiences candidates shared, not from Microsoft materials.
134
candidate reports
39
distinct questions
7
round types
Monthly
refresh cadence
Key facts
- •39 distinct Microsoft interview questions indexed
- •134 candidate reports across the catalog
- •Most reported: Behavioral, Hiring Manager and "As Appropriate" Questions — 12× (last seen September 2026)
- •Round mix across candidate reports: coding 39%, phone screen 15%, system design 12%, ML / research 10%, online assessment 10%, behavioral 9%, technical deep-dive 5%
- •18 of the 39 questions were last reported in Aug–Oct 2026
- •Reports span Oct 2025 – Oct 2026
- •Refreshed monthly · last updated October 2026
Browse Microsoft interviews by topic
The Microsoft loop, from candidate reports
Reported Microsoft software engineering loops vary by team and by route. Hiring events start with a HackerRank online assessment of two problems, such as a balanced permutation check or the cheapest trip when fuel prices differ by city, then four rounds in one morning: three coding rounds and one system design. Team loops start with a phone screen that often spends time on a past project before one coding problem. Onsite coding is mostly LeetCode-style, with Number of Islands and its variants, LRU Cache, a rate limiter and Merge Intervals reported most, plus object-oriented and concurrency problems such as a per-key ordered task executor. MAI and Copilot teams ask more practical multi-part problems: DNA fragment assembly, stop-token detection over a stream of text, beam search decoding and an in-memory table built from CSV. System design rounds most often cover ticket booking, a URL shortener, re-engagement for inactive Copilot users, an online multiplayer game and log storage. Most rounds open with behavioral questions, many loops include a hiring-manager round or a project deep dive, and some 2026 loops add an AI-assisted coding round.
What does Microsoft ask in each interview round?
Microsoft interviews span 7 distinct round types, broken down below. Counts reflect distinct questions per round, not number of times asked. Frequencies on individual question cards show how many candidates reported getting that specific question.
LeetCode-style problems (Number of Islands and its variants, LRU and LFU Cache, Merge Intervals, Lowest Common Ancestor, Spiral Matrix, Alien Dictionary, distance to a cycle) and practical ones (a sliding-window rate limiter, a per-key ordered task executor, an in-memory table from CSV).
17 questions
Most-reported: Number of Islands and Its Variants (Islands II, Largest Island, Region Sizes) (7 reports)
A coding screen, often after a project discussion: DNA fragment assembly, stop-token detection over a text stream, suffix-maximum counts, top K problems, package install order and Longest Palindromic Subsequence.
6 questions
Most-reported: Top K: Largest Elements, Most Frequent, Ranked Apps and Stores (7 reports)
Two HackerRank problems: a balanced permutation check, the maximum XOR product, counting non-decreasing arrays with given digit sums, the cheapest trip with fuel prices by city, the most frequent substring within limits, and picking k non-adjacent servers.
6 questions
Most-reported: OA: Balanced Permutation (Is 1..k a Contiguous Block, for Every k) (3 reports)
Ticket booking, a URL shortener, re-engagement for inactive Copilot users, an online multiplayer game and log storage, plus many designs drawn from the interviewing team's own work.
5 questions
Most-reported: Design a Ticket Booking System (Ticketmaster / Cinema Seats) (4 reports)
ML coding (greedy decoding then beam search, k-means from scratch) and applied scientist ML fundamentals such as bagging versus boosting, metrics and regularization.
3 questions
Most-reported: Applied Scientist ML Fundamentals: Bagging vs Boosting, Metrics, Regularisation, Model Choice (6 reports)
Behavioral questions in most rounds and in hiring-manager rounds: conflict, a hard project, a missed deadline, changing requirements and why Microsoft.
1 question
Most-reported: Behavioral, Hiring Manager and "As Appropriate" Questions (12 reports)
A project deep dive or resume technical review: detailed questions on a past system, your own decisions and trade-offs, in one report latency layer by layer.
1 question
Most-reported: Project Deep Dive / Resume Technical Review (7 reports)
Which Microsoft interview questions come up most?
These are the Microsoft questions reported most across the loops we’ve indexed, sorted by candidate-report frequency.
| Question | Round | Reported | Last seen |
|---|---|---|---|
| Behavioral, Hiring Manager and "As Appropriate" Questions | Behavioral | 12× | September 2026 |
| Project Deep Dive / Resume Technical Review | Tech Deep Dive | 7× | June 2026 |
| Top K: Largest Elements, Most Frequent, Ranked Apps and Stores | Phone Screen | 7× | September 2026 |
| Number of Islands and Its Variants (Islands II, Largest Island, Region Sizes) | Coding | 7× | September 2026 |
| Applied Scientist ML Fundamentals: Bagging vs Boosting, Metrics, Regularisation, Model Choice | MLE | 6× | April 2026 |
| LRU Cache, Then Thread Safety, Expiry and Sharding | Coding | 6× | October 2026 |
| Rate Limiter: Sliding-Window allow(), Then 100K QPS | Coding | 5× | April 2026 |
| Merge Intervals, Then Return Every Overlapping Interval | Coding | 4× | April 2026 |
| DNA Fragment Assembly: Chain by Tags, Then Unknown Direction, Then Several Chains | Phone Screen | 4× | May 2026 |
| Binary Tree Zigzag Level Order Traversal | Coding | 4× | August 2026 |
The full index is below, or browse the Microsoft catalog →
Every Microsoft interview question we’ve indexed
All 39, grouped by round and sorted by how often candidates reported them. Each links to the question, its reported follow-up count, and when it was last seen.
Coding (17)
- Number of Islands and Its Variants (Islands II, Largest Island, Region Sizes) — reported 7×, last seen September 2026
- LRU Cache, Then Thread Safety, Expiry and Sharding — reported 6×, last seen October 2026
- Rate Limiter: Sliding-Window allow(), Then 100K QPS — reported 5×, last seen April 2026
- Merge Intervals, Then Return Every Overlapping Interval — reported 4×, last seen April 2026
- Binary Tree Zigzag Level Order Traversal — reported 4×, last seen August 2026
- In-Memory Table from CSV: Parse, Select Columns, WHERE Filters, ORDER BY — reported 4×, last seen May 2026
- LFU Cache — reported 2×, last seen April 2026
- Word Break II: Rebuild a Sentence from a Dictionary (Backtracking + Memo) — reported 2×, last seen October 2026
- Longest Substring Without Repeating Characters — reported 2×, last seen January 2026
- Calendar: Can a New Event Be Scheduled Without Overlap (My Calendar I) — reported 2×, last seen March 2026
- Distance from Every Node to the Cycle in a Graph — reported 2×, last seen January 2026
- Lowest Common Ancestor: BST First, Then Any Binary Tree — reported 2×, last seen February 2026
- Spiral Matrix: Clockwise, Counter-Clockwise, Then Generate N x N — reported 2×, last seen August 2026
- Palindrome Linked List in O(1) Space, Then Restore the List — reported 2×, last seen August 2026
- Is a Number a Palindrome, Then the Next Larger Palindrome — reported 2×, last seen January 2026
- Per-Key Ordered Task Executor (Same Key in Order, Bounded Concurrency, Shutdown) — reported 2×, last seen September 2026
- Alien Dictionary (Topological Sort; Empty String if Invalid) — reported 2×, last seen August 2026
Phone Screen (6)
- Top K: Largest Elements, Most Frequent, Ranked Apps and Stores — reported 7×, last seen September 2026
- DNA Fragment Assembly: Chain by Tags, Then Unknown Direction, Then Several Chains — reported 4×, last seen May 2026
- Stop-Token Detection over a Stream of Text Chunks (Token Split Across Chunks) — reported 3×, last seen February 2026
- For Each Query Index, Count the Maximum of the Suffix — reported 2×, last seen August 2026
- Longest Palindromic Subsequence — reported 2×, last seen December 2025
- Package Install Order from Dependencies (Topological Sort, Raise on Cycles) — reported 2×, last seen February 2026
OA (6)
- OA: Balanced Permutation (Is 1..k a Contiguous Block, for Every k) — reported 3×, last seen March 2026
- OA: Most Frequent Substring Within Length and Unique-Letter Limits — reported 2×, last seen October 2026
- OA: Count Non-Decreasing Arrays with Given Digit Sums — reported 2×, last seen October 2026
- OA: Maximise (A xor X) * (B xor X) for X < 2^N, Modulo 1e9+7 — reported 2×, last seen July 2026
- OA: Pick K Non-Adjacent Servers, Minimise the Largest Pick — reported 2×, last seen October 2026
- OA: Cheapest Trip When Fuel Price Differs by City (Dijkstra with State) — reported 2×, last seen August 2026
System Design (5)
- Design a Ticket Booking System (Ticketmaster / Cinema Seats) — reported 4×, last seen April 2026
- Design a URL Shortener (Multi-Region Reads, Write Spikes, Then Code It) — reported 4×, last seen June 2026
- Design a Re-Engagement System for Inactive Copilot / ChatGPT Users — reported 3×, last seen May 2026
- Design an Online Multiplayer Game (Chess.com, Tic-Tac-Toe, Real-Time Matches) — reported 3×, last seen October 2026
- Design a Log Storage System (Massive Writes, Tailing Readers) — reported 2×, last seen October 2026
MLE (3)
- Applied Scientist ML Fundamentals: Bagging vs Boosting, Metrics, Regularisation, Model Choice — reported 6×, last seen April 2026
- ML Coding: Greedy Decoding, Then Beam Search with Sentence Probabilities — reported 4×, last seen September 2026
- ML Coding: Implement K-Means from Scratch — reported 4×, last seen May 2026
Behavioral (1)
- Behavioral, Hiring Manager and "As Appropriate" Questions — reported 12×, last seen September 2026
Tech Deep Dive (1)
- Project Deep Dive / Resume Technical Review — reported 7×, last seen June 2026
What passing candidates do
- •Running your code against your own tests. Several reports say rounds expected a main function or test cases that run, not a dry run, and one new grad loop expected every follow-up written out.
- •Preparing the concurrency follow-up. LRU Cache and the hash map are followed by multi-threaded access, the rate limiter by 100,000 requests a second, and the per-key executor asks for per-key ordering under a global concurrency limit.
- •Taking multi-part MAI problems one part at a time. DNA assembly moves from tags with a known direction to an unknown direction and then several chains, and the CSV table from parsing to selecting columns to WHERE filters.
- •Being ready to code part of your design. Some design rounds end with implementation, such as URL shortener code on HackerRank or the trie behind a typeahead.
Where candidates lose points
- •Recursive DFS on large grids. On the region-size problem, one interviewer asked what is wrong with DFS; the candidate's answer was stack overflow on large input, fixed with a queue.
- •Brute force on the OA. Slower solutions timed out on hidden tests, including on the fuel-cost graph problem.
- •Buffering the whole stream in stop-token detection. One report says text must be returned as chunks arrive, with the stop token possibly split across chunks.
- •Skimming the CSV rules. In the in-memory table problem, quoted values, commas inside quotes and type casting cost candidates the later parts.
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Send them this guide: 39 questions from 134 candidate reports, with the rounds, the follow-ups and what passers do.