LeetCode Microsoft Interview: Top Problems and Prep Guide

Microsoft is one of the largest employers of software engineers in the world. With teams spanning Azure, Office 365, Windows, LinkedIn, GitHub, and Xbox, the company runs thousands of interview loops every year across dozens of offices. If you are preparing for a LeetCode Microsoft interview, you are targeting one of the most accessible paths into big tech.

What sets Microsoft apart from other FAANG companies is the interview culture. Microsoft interviewers are genuinely collaborative — they want to see you succeed and will often nudge you toward the right approach rather than silently watch you struggle. This does not mean the bar is lower. It means the evaluation focuses on how you think, communicate, and write clean code under guidance.

Microsoft also places a stronger emphasis on object-oriented programming and design patterns than most competitors. While Google and Meta lean heavily on raw algorithmic ability, Microsoft values engineers who can discuss SOLID principles, write production-quality classes, and reason about system architecture alongside solving algorithm problems.

In this guide, you will learn exactly what to expect in the Microsoft SWE interview process, which LeetCode problems appear most frequently, and how to structure a prep plan that covers both algorithms and the OOP skills Microsoft values.

The Microsoft coding interview follows a structured pipeline that typically spans two to four weeks from first contact to offer. Understanding each stage helps you allocate your prep time effectively and avoid surprises on interview day.

The process begins with a recruiter screen — a 30-minute call focused on your background, role interest, and basic technical qualifications. No coding happens here, but the recruiter may ask about your experience with specific technologies or system design concepts. If you pass, you move to the phone screen.

The Microsoft phone screen is a single 45-to-60-minute coding interview conducted over a shared editor. You will receive one or two algorithm problems at the easy-to-medium level. The interviewer evaluates your problem-solving approach, coding fluency, and ability to communicate your thought process. Most candidates who prepare with LeetCode medium-level problems pass this stage.

The onsite loop is where Microsoft differs most from other companies. You will complete four to five rounds in a single day: two to three coding rounds, one system design round, and one behavioral round with the hiring manager. Each coding round is 45 minutes with a different interviewer, and problems range from medium to hard difficulty.

Microsoft interview questions cluster around a specific set of patterns that reflect the company's engineering culture. While you should have breadth across all major categories, these are the patterns that appear most frequently in reported Microsoft interviews.

Trees and linked lists dominate Microsoft coding rounds. BST validation, tree traversal variants (inorder, preorder, level-order), and linked list manipulation (reversing, merging, cycle detection) appear in a disproportionate share of reported questions. If you can solve tree and linked list problems confidently, you have covered a large portion of what Microsoft asks.

Arrays and strings are the second most common category, often paired with hash map usage. Problems involving substring search, anagram detection, and matrix traversal come up regularly. Microsoft also tests dynamic programming more than some candidates expect — especially tabulation-style problems where you build a solution from smaller subproblems.

Finally, Microsoft stands out for testing OOP design within coding rounds. You may be asked to design a class hierarchy, implement an interface, or discuss design patterns like Observer or Strategy as part of a coding problem. This is rare at Google or Meta but common at Microsoft.

Based on interview reports, discussion forums, and frequency data, these twelve problems represent the core of what Microsoft asks in coding interviews. Focus on understanding the patterns behind each one rather than memorizing solutions — Microsoft interviewers will probe your understanding with follow-ups.

Start with Reverse Linked List (#206) and Merge Two Sorted Lists (#21). These two problems cover the fundamental linked list manipulation techniques that Microsoft tests repeatedly. If you can reverse a list iteratively and recursively, and merge two sorted lists in O(n) time, you have the building blocks for most linked list questions.

Validate Binary Search Tree (#98) and Binary Tree Level Order Traversal (#102) cover the tree fundamentals. Microsoft loves BST problems because they test recursion, boundary handling, and your understanding of tree invariants. Level-order traversal tests BFS and is a building block for many follow-up questions.

For arrays and strings, focus on Spiral Matrix (#54), String to Integer (#8), and Add Two Numbers (#2). These problems test careful implementation, edge case handling, and the kind of production-quality thinking Microsoft values. Spiral Matrix in particular tests your ability to manage complex indices without bugs.

At the medium-to-hard level, practice LRU Cache (#146), Word Search (#79), and Serialize and Deserialize Binary Tree (#297). LRU Cache combines hash maps with doubly-linked lists and is one of the most frequently reported Microsoft problems. Word Search tests backtracking on a grid, and Serialize/Deserialize tests tree traversal depth.

Round out your list with Copy List with Random Pointer (#138) and Group Anagrams (#49). Copy List tests your ability to handle complex pointer manipulation, while Group Anagrams is a clean hash map problem that Microsoft uses to evaluate coding fluency.

Microsoft's interview culture is genuinely different from the rest of big tech, and understanding these differences can give you a real edge in your preparation. The collaborative atmosphere is not just a rumor — it is built into how interviewers are trained.

At Google or Meta, interviewers typically stay quiet and observe how you work through a problem independently. At Microsoft, interviewers are encouraged to have a conversation with you. They will ask clarifying questions, suggest you consider edge cases, and sometimes hint at a better approach if you are going down the wrong path. This means your communication skills matter as much as your coding speed.

Microsoft's OOP focus is another major differentiator. While other companies may ask you to implement a function, Microsoft may ask you to design a class with specific methods, discuss inheritance versus composition, or explain why you chose a particular design pattern. If you have worked with C# or Java extensively, this will feel natural. If your background is primarily Python, spend time reviewing OOP concepts before your interview.

Team-matching is another unique aspect. Unlike Google, where you interview for a general pool and get matched to a team later, Microsoft often interviews you for a specific team. This means the interviewers are your potential future colleagues, and the problems may reflect the team's domain. Ask your recruiter which team you are interviewing with and research what they build.

Knowing the format and problems is only half the battle. These Microsoft-specific strategies will help you stand out during your interview loop and demonstrate the qualities that Microsoft hiring committees prioritize.

Write clean, production-quality code from the start. Microsoft values readability and maintainability more than other FAANG companies. Use descriptive variable names, add brief comments for complex logic, handle edge cases explicitly, and structure your code with clear helper methods. Do not write spaghetti code and clean it up later — Microsoft interviewers notice how you write code, not just whether it works.

Discuss OOP principles proactively. When designing a solution, mention relevant SOLID principles — single responsibility for helper methods, open-closed when designing extensible solutions, dependency inversion when discussing interfaces. You do not need to lecture on design patterns, but weaving OOP vocabulary into your explanation signals that you think like a Microsoft engineer.

Communicate trade-offs explicitly. Before writing code, discuss at least two approaches and explain why you are choosing one over the other. Microsoft interviewers want to see that you can reason about time-space trade-offs, scalability implications, and real-world constraints. Saying "I could use a hash map for O(1) lookup at the cost of O(n) space, or sort first for O(n log n) time with O(1) space" shows engineering judgment.

Ask clarifying questions early and often. Microsoft interviewers expect you to clarify constraints, input ranges, and edge cases before coding. This is not a sign of weakness — it is how senior engineers work. Ask about null inputs, empty arrays, integer overflow, and duplicate values before writing a single line of code.

A structured prep plan is the fastest way to build confidence for your Microsoft SWE interview. This four-week plan balances algorithm practice, OOP review, and flashcard-based retention using YeetCode to make sure you remember what you study.

In week one, focus on the fundamentals that Microsoft tests most: linked lists and trees. Solve Reverse Linked List, Merge Two Sorted Lists, Validate BST, and Level Order Traversal. After solving each problem, create a YeetCode flashcard capturing the pattern and key insight. Review your cards daily — spaced repetition is how you move from "I solved it once" to "I can solve it in an interview."

Week two shifts to arrays, strings, and hash maps. Work through Spiral Matrix, String to Integer, Add Two Numbers, and Group Anagrams. Practice writing clean code with good variable names and edge case handling from the start. Continue reviewing your week one flashcards alongside new ones.

In week three, tackle the harder problems: LRU Cache, Word Search, Serialize and Deserialize Binary Tree, and Copy List with Random Pointer. Also dedicate two or three sessions to OOP design practice — implement a parking lot system, a deck of cards, or a file system using classes and interfaces. These OOP exercises prepare you for the design-oriented questions Microsoft loves.

Week four is consolidation. Do two to three mock interviews with a timer, focusing on the full 45-minute format. Practice explaining your approach before coding, discussing trade-offs, and testing your solution out loud. Use YeetCode to review all your flashcards daily, focusing on any patterns that still feel shaky. By the end of this week, the top Microsoft patterns should feel automatic.