Microsoft Senior SE (L63/L64) Interview Experience | March 2026
Summary
I interviewed for a Senior Software Engineer position on the Azure Storage team at Microsoft, completing four rounds (DSA, LLD, system design, and behavioral) with strong feedback, but the role was filled internally.
Full Experience
Timeline - March 18th 2026 to March 24th 2026 YOE (then) : 8.5+ Years Current (Most Recent Company) : SMTS(IC3) at Oracle (Laid off in September 2025) College - IITK
Directly applied on their portal, Recruiter reached out to me directly on LinkedIn as well and I got interviewd by Microsoft Azure Storage Org/Team for a Senior Software Enginner role in March end and here's the experience -
R1(DSA Coding on HackersRank) -
- Implement LRU cache with TTL in it (https://leetcode.com/problems/lru-cache/description/ + TTL)
- How would you implement concurrency in it?
- Was able to implement a working solution with test cases passed and was able to explain the concurrency part as well.
R2(LLD) - Was supposed to be LLD but it was taken by Hiring Manager and this is what he discussed
- Intro and Most critically challanging past project (around 10-15 minutes)
- Design a configuration service which is responsible for updating configurations existing on n number of microservices existing in our architecture - High level System design discussion (arond 25-30 minutes)
- LRU Pseudo code and concurrency part of it - Also, if there are more cache misses than hits, how would you figure out if the problem is with cache size or cache policy? What all disgnosis you'll do? (last 10-15 minutes)
- Discussion went really well again and the interviewer was satisfied.
Both round happened on same day with 1 hour gap and got strong feedback in both of them. Recruiter reached out and scheduled my 3rd and 4th round after 3-4 days on back to back days.
R3(System Design by a Principal Engineer) -
- High level system design and data flow discussion of my current project (around 30 minutes)
- Design a File System - Interviewer actually mentioned that I want to discuss this since you're getting interviewed for Azure "Storage" org. Instead of discussiong typical fancy System design stuff like Scale/reliability/CAP etc tradeoffs, he probed into the very basics of Storage systems like How a file is actually saved on a disk. Which underlyting Data-Structures (like BitMap) are used to mark the free spaces(chunks) etc.
- This round went decent (not so great, neither bad since I don't have past experience particulary in storage domain). I think Microsoft is moving towards Org/Team/Role specific interviews instead of asking irrelavant questions like Design Twitter/Youtube for 1 Billion users in 45 minutes stuff!
R4 (AA (As Appropriate) Round by Senior Principal Manager/Director) -
- In depth discussion on past projects and my stories, answered using STAR/CARL format.
- Typical behavioral questions like resolving conflicts and why Microsoft etc?
- The interviewer also mentioned that he has 2 reqs under him in 2 different teams and which one I would like to join? Kind of did the team matching there itself.
Final Veridct - I called the recruiter on next Monday and she mentioned that the Director really liked you and it's a strong feedback from all rounds but They have identified a candidate internally and the position got filled. Also conveyed that if the same guy gets another SSE req in his team in future, he would reach out to me.
- I was totally disappointed and heartbroken. This happened with me second time back to back after Atlassian went on hiring freeze in Jan. And specially because I was enemployed for 6+ months now, it hurt me more.
Recuiter mentioned that they will try to pass on my feedback to other Managers but they can take 1-2 rounds (specially AA round) again.
I got one interview next week but that went Okayish and I wasn't recommended by him for his team.
Final update from recruiter was that my feedback is preserved and they will try to find a team that has req but since Microsoft Financial Year End is in May so it all slowed down. I have kind of moved on and gave interviews in few other companies. Not really sure they will get back to me.
Interview Questions (5)
Implement LRU Cache with TTL
Design and implement an LRU (Least Recently Used) cache that supports a Time‑To‑Live (TTL) for each entry. The implementation should provide get and put operations, evict the least recently used items when capacity is exceeded, and automatically remove entries whose TTL has expired.
Implement Concurrency for LRU Cache
Explain how you would make the LRU cache thread‑safe and handle concurrent get/put operations, including any synchronization mechanisms or lock‑free approaches you would use.
Design Configuration Service for Microservices
Design a high‑level configuration service responsible for updating configurations across an arbitrary number of microservices in an architecture. Discuss components, data flow, consistency, and scalability considerations.
Diagnose Cache Misses vs Hits
Given a scenario where cache misses exceed hits, describe how you would determine whether the issue is due to cache size or cache eviction policy, and outline the diagnostics you would perform.
Design a File System (Storage Basics)
Design a file system focusing on low‑level storage details: how a file is saved on disk, which underlying data structures (e.g., bitmap) are used to track free space, and how the system manages allocation and deallocation of blocks.