Microsoft is one of the biggest tech companies in the world. It’s known for creating revolutionary products like Windows, Microsoft Office, Azure Cloud, and Surface devices. Millions of people and businesses worldwide use Microsoft’s tools and services daily. Beyond its products, the company is known for its collaborative work culture, focus on new ideas, and a mission to “empower every person and every organization on the planet to achieve more.”
Many people want a job at Microsoft, but the interview process is tough. You need strong technical skills to succeed. It’s also important to research Microsoft’s values, such as putting customers first, respecting diverse backgrounds, and being open to learning and growth.
This blog will cover everything you need to prepare for Microsoft’s interviews. We’ll cover key areas like coding, system design, and behavioral interviews to help you succeed throughout the interview process.
Coding interview questions
The coding interview is a key stage in Microsoft’s hiring process. It evaluates your problem-solving skills, algorithmic thinking, and familiarity with data structures.
Below, we’ve curated some of the top LeetCode problems commonly asked in Microsoft interviews. These questions cover sliding window, binary search, graphs, and dynamic programming patterns.
1. Two sum
Problem statement: Given an array of integers, nums, and a target integer, target, return the indexes of the two numbers that add up to the target.
It’s important to note that each input has exactly one solution, and you may not use the same element twice. Additionally, the answer can be returned in any order.
Example:
Input:
nums = [2, 7, 11, 15]
target = 9
Output:
[0, 1]
Solution:
One optimal solution is to use a hash map to store the numbers we have seen and their indexes. As we iterate through the array, we check if the complement (target - current number) is already in the hash map for each number. If it is, we return the indexes of the current number and its complement. Otherwise, we store the current number and index in the hash map. This approach finds the solution in a single pass.
Solution Code:
Two Sum
Complexity analysis:
Each element is processed once, so, it takes \( O(n) \) time. The hash map can store at most \( n \) elements, so the space complexity of this solution is \( O(n) \).
Problem statement: Given a string, s, find the length of the longest substring without repeating characters.
Example:
Input:
s = “abcabcbb”
Output:
3
Explanation: The answer is “abc” with a length of 3.
Solution:
One of the optimal solutions to this problem uses the sliding window technique and a hash map to track the last seen positions of characters. The idea is to maintain a window containing unique elements by dynamically adjusting its starting point as we scan the data.
As we iterate through the sequence, if we encounter an element that has already appeared within the current window, we shift the start of the window just past its last known position. This ensures that the window continues to contain unique elements. We then update the element’s latest position in the map. We measure the window size at each step and keep track of the maximum size encountered. After examining the entire sequence, the largest window size represents the length of the longest segment with all unique elements.
Solution Code:
Longest substring without repeating characters
Complexity analysis:
Because each character is processed at most twice, this approach runs in \( O(n) \) time, where \( n \) is the length of the string. This solution uses \( O(min(n,m)) \) space, where m is the size of the character set, e.g., 26 for lowercase English letters.
Problem statement: Given an array of intervals representing each interval as [starti, endi], merge all overlapping intervals and return a new array containing the non-overlapping intervals that fully cover the original set of intervals.
Example:
Input:
intervals = [[1, 3], [2, 6], [8, 10], [15, 18]]
Output:
[[1, 6], [8, 10], [15, 18]]
Solution:
One of the optimal solutions is to first sort the intervals based on their starting points. Then, we iterate through the sorted list, maintaining a merged list. If each interval overlaps with the last interval in the merged list (i.e., its start is within the last interval’s range), we merge them by updating the end time to the maximum of both intervals. Otherwise, we simply add the interval to the merged list. This ensures all overlapping intervals are combined while keeping non-overlapping ones separate.
Solution Code:
Merge intervals
Complexity analysis:
The time complexity of this approach is \( O(n \log n) \) due to the sorting step, while the merging step runs in \( O(n) \), where \( n \) is the number of intervals. The space complexity is \( O(n) \).
Problem statement: You are given two integer arrays, nums1 and nums2, sorted in non-decreasing order, and two integers, m and n, representing the number of elements in nums1 and nums2, respectively.
Your task is to merge nums2 into nums1 as one sorted array. The merged array should also be sorted in non-decreasing order. It’s important to note that nums1 has a size of m + n, where the last n elements are set to 0 and should be replaced by elements from nums2.
Example:
Input:
nums1 = [4, 8, 9, 0, 0, 0], m = 3nums2 = [1, 2, 7], n = 3
Output:
[1, 2, 4, 7, 8, 9]
Solution:
One of the most efficient ways to solve this problem is by using a two-directional comparison strategy, beginning from the end of both arrays. As the first array has additional space to accommodate all elements, the idea is to fill it from the back with the largest values first. By repeatedly comparing the largest unplaced elements from each array, the greater one is placed at the next available position from the end. Once all elements from the second array have been placed, the result is a fully merged and sorted array. This approach ensures an efficient in-place merge without needing extra space.
Solution Code:
Merge sorted array
Complexity analysis:
The time complexity of this approach is \( O(m+n) \) as we traverse both arrays once. The space complexity is \( O(1) \) as we modify nums1 in place without using extra space.
Additional coding questions
After a few detailed examples, here are some additional LeetCode-style coding questions that you can practice to prepare for your Microsoft interview.
| Problem | Description |
|---|---|
| Number of Islands | Given a 2D grid of 1s (land) and 0s (water), count the number of disconnected islands formed by connected land cells. |
| Median of Two Sorted Arrays | Given two sorted arrays, find the median of the combined array in logarithmic time. |
| Single Number | Given an array where every element appears twice except for one, return the element that appears only once. |
| Frequency of the Most Frequent Element | Given an array and an integer k, return the maximum frequency of any element you can achieve by incrementing elements at most k times. |
| Subarray Sum Equals K | Given an array of integers and an integer k, find the total number of continuous subarrays that sum up to k. |
| Move Zeroes | Given an array, move all 0s to the end while maintaining the order of non-zero elements. |
System Design interview questions
In Microsoft’s system design interview, candidates are tested on their ability to design scalable, efficient, and reliable systems. You’ll typically discuss high-level architecture, trade-offs, and how to handle real-world challenges like latency, fault tolerance, and scalability.
The questions in Microsoft’s System Design interview become easier to tackle when you understand common System Design principles and practice designing real-world systems. The “Grokking the System Design Interview” course is a great resource to build this expertise.
Below are examples of some common design prompts at Microsoft, with key features to include and high-level design highlights.
Objective: Create a system that converts long URLs into shorter ones, ensuring scalability, uniqueness, and efficient redirection.
- Key features:
- Short URL generation: Create unique, compact short links for any long URL.
- Redirection: Redirect users quickly from the short URL to the original long URL.
- Analytics: Track usage stats like click counts, referring sites, and geolocation.
- Scalability: Handle high read/write traffic and ensure low-latency access.
- Design highlights:
- Key generation: Use Base62 encoding or hash functions for short URL creation.
- Database: Use a scalable key-value store (e.g., DynamoDB, Cassandra) to map short and long URLs.
- Cache: Use Redis or Memcached to cache frequently accessed short URLs.
- Analytics: Store analytics events asynchronously via message queues (Kafka/RabbitMQ).
- Rate limiting: Add API rate limiting and abuse detection.
- Load balancing: Distribute incoming traffic using a load balancer or global DNS-based routing.
What is being tested? This question assesses your ability to design an efficient and scalable system to handle many requests with minimal latency.
Objective: Build a real-time messaging platform that supports one-on-one and group chats, message delivery guarantees, and message history.
- Key features:
- Messaging: Real-time messaging with delivery/read receipts.
- Presence: Show online/offline/typing indicators.
- Group chat: Support for chat rooms with many participants.
- Message history: Store and sync messages across devices.
- Design highlights:
- Protocols: Use WebSockets for real-time messaging and fall back to long polling if needed.
- Microservices: Separate services for messaging, user presence, and notifications.
- Storage: Use scalable databases (e.g., Cassandra for messages, Redis for presence).
- Message queue: Use Kafka or RabbitMQ to decouple sending and storing messages.
- Sync: Ensure consistent message ordering and syncing across devices.
- Security: Encrypt messages in transit and at rest.
What is being tested? This question evaluates your understanding of real-time communication systems and ability to design features ensuring message reliability and scalability.
Objective: Develop a system that allows users to efficiently upload, store, and stream videos to a global audience.
- Key features:
- Video upload: Users can upload large video files.
- Encoding: Transcode videos into multiple formats/resolutions for playback.
- Streaming: Serve videos to users with minimal buffering and adaptive quality.
- Content discovery: Search, recommend, and categorize videos.
- Design highlights:
- Storage: Use blob storage (e.g., AWS S3, Azure Blob) for storing video files.
- Encoding pipeline: Queue uploaded videos for background processing/transcoding.
- CDN: Distribute video content via a Content Delivery Network to reduce latency.
- Database: Use SQL for user/video metadata, and Elasticsearch for search.
- Caching: Cache popular video metadata and thumbnails.
- Monitoring: Track metrics like video watch time, errors, and CDN performance.
What is being tested? This question tests your knowledge of media streaming, content distribution, and system optimization for diverse user environments.
Additional System Design problems
The more you practice, the better you get. Let’s quickly look at a few other examples of System Design problems.
| Problem | Description |
|---|---|
| Scalable e-commerce platform | Support product listings, user carts, payments, and order tracking with high availability and performance. |
| Ride-sharing application like Uber | Match riders with nearby drivers, enable real-time tracking, and handle dynamic pricing and route optimization. |
| File storage and sharing service like Google Drive | Users can upload, store, organize, and securely share files with real-time sync and access control. |
| Dynamic pricing system for delivery fees | Set delivery fees that adjust in real time based on demand, weather, distance, etc. |
| Scalable notification system | Send millions of real-time notifications across push, SMS, and email channels. |
| Scalable payment processing system | Securely process payments and payouts while handling fraud, retries, and gateway failures. |
Behavioral interview questions
Microsoft’s behavioral interviews assess how well candidates embody their leadership principles, work collaboratively, and handle challenges. The STAR method (situation, task, action, result) is an excellent framework for structuring your responses.
Let’s look at some common Microsoft behavioral questions, with tips and example answers:
1. Tell us about a time you had to work with someone difficult.
Tip: Microsoft values collaboration and a growth mindset. When answering, focus on how you navigated the challenge constructively and what you learned from the experience.
Example answer:
- Situation: In a previous project, I was assigned to work with a colleague who had a different communication style and often dismissed others’ ideas.
- Task: Our goal was to develop a new feature for our product within a tight deadline.
- Action: I initiated one-on-one meetings to understand his perspective and find common ground. I also suggested setting clear roles and responsibilities to minimize conflicts.
- Result: Our collaboration improved, leading to the successful delivery of the feature on time. This experience taught me the importance of proactive communication and empathy in team dynamics.
2. Describe a time when you had to quickly learn something new to complete a task.
Tip: This question assesses adaptability and a growth mindset. Highlight your ability to learn and apply new information efficiently.
Example answer:
- Situation: I was assigned a project that required knowledge of a programming language I had never used before.
- Task: I needed to develop a module using this language within two weeks.
- Action: I dedicated time to online tutorials and consulted with colleagues experienced in the language. I also practiced by working on small code snippets to build my proficiency.
- Result: I successfully developed the module within the deadline, and it passed all quality checks. This experience reinforced my confidence in quickly acquiring new skills when needed.
3. Tell us about a time you failed and what you learned from it.
Tip: Microsoft looks for candidates who can reflect on failures and extract lessons. Be honest about the failure and focus on the insights gained.
Example answer:
- Situation: I led a project that aimed to implement a new internal tool, but we missed the launch deadline due to underestimating the complexity.
- Task: As the project lead, I was responsible for planning and execution.
- Action: After the delay, I conducted a retrospective with the team to identify what went wrong. We realized our initial time estimates were overly optimistic and hadn’t accounted for potential technical challenges.
- Result: I learned the importance of thorough risk assessment and realistic planning. In subsequent projects, I implemented more rigorous planning processes, which led to improved on-time deliveries.
Additional behavioral questions
To get you interview-ready, let’s go over some more example behavioral questions:
| Competency | Example Behavioral Questions |
|---|---|
| Customer obsession | Tell us about when you went above and beyond to meet a customer’s needs. |
| Integrity and ethics | Describe a situation where you were faced with an ethical dilemma. How did you handle it? |
| Initiative | Can you provide an example of when you identified a problem and took the initiative to solve it without being asked? |
| Communication | Tell us about when you had to explain a complex concept to someone without a technical background. |
| Leadership | Describe a situation where you had to lead a team through a challenging project. What was your approach? |
Recommended resources
- Grokking the Coding Interview Patterns: Master 26 essential coding patterns to solve thousands of LeetCode-style questions. Efficiently prepare for coding interviews with the ultimate course created by FAANG engineers.
- Grokking the Modern System Design Interview: This is the ultimate guide to the System Design interview, developed by FAANG engineers. Master distributed system fundamentals and practice with real-world interview questions and mock interviews.
- Grokking the Behavioral Interview: Whether you’re a software engineer, product manager, or engineering manager, this course will give you the tools to thoroughly prepare for behavioral and cultural questions. But beyond even technical roles, this would be useful for anyone in any profession.
- Grokking the Product Architecture Design Interview: This is an essential guide to API design and product design interviews, developed by FAANG engineers. Master product design fundamentals and get hands-on with real-world APIs.
- Educative’s AI mock interviews: These give you a real feel of actual interviews, with questions across many topics. You can practice specific areas like Dynamic Programming or try full interviews that cover a variety of skills. This helps you build confidence, improve your answers, and prepare for the real thing.
Landing a position at Microsoft is a rewarding challenge that requires a mix of technical expertise, strategic thinking, and cultural alignment. With structured preparation and a focus on problem-solving, you can confidently approach the interview process. Remember, Microsoft looks for skilled individuals passionate about making an impact. Good luck!
Educative’s new product, PAL (Personalized Adaptive Learning), revolutionizes interview preparation by creating a customized roadmap for you. PAL lets you seamlessly navigate between question difficulties—start with medium, try harder when you’re ready, or go back to easier ones to better understand the topic. This way, you learn at your own pace and get stronger step by step.
Frequently Asked Questions
What programming languages are preferred in Microsoft interviews?
Microsoft allows candidates to use any mainstream programming language, such as Python, Java, C++, or C#.
How many rounds are there in Microsoft’s interview process?
Typically, there are 4–5 rounds, including coding, system design, and behavioral interviews.
Is System Design asked for junior-level roles?
System Design is generally reserved for mid-to-senior roles. However, juniors may be asked simplified design questions.
How should I prepare for behavioral questions?
Use the STAR method and reflect on past experiences, highlighting your skills, leadership, and ability to overcome challenges.
What is the best way to practice for Microsoft coding interviews?
Focus on practicing coding questions and mock interviews. Educative, LeetCode, and HackerRank are great resources to practice coding questions from.
Company Interview Questions
