Microsoft SDE-II Level 61 Interview Experience 2025 (Selected)
3 years of experience, applied through the official careers portal (not referral - the referral queue is way too long), and got the offer last week.
Getting to the interviews
Applied through Microsoft's careers portal roughly 20 times across different openings. Got test links 3 times total but cleared the first one so the other two never went further.
The online assessment was on HackerRank, 90 minutes. Harder than the actual rounds honestly. One problem required Dijkstra + DFS, another was C(n,k) combinatorics with modular arithmetic. Completed the first test fully, got around 80% on the second. Time pressure was rough.
The interview rounds (August 1-8, fully virtual)
Round 1 was DSA, 60 minutes. Three problems: Rotten Oranges, check if a binary tree is a valid BST, and find the two swapped nodes in a BST. Fundamentals round, nothing too surprising.
Round 2 was Low Level Design: a Post Office system. This one caught me off guard. Design a system that consumes letters from one end and distributes them to multiple postmen efficiently. Core entities were PostOffice, Letter, DeliveryPerson, and Route. We got deep into concurrency - handling multiple delivery workers processing letters in parallel. I hadn't prepped this specific scenario but had built a telemetry logger during prep and borrowed those patterns. Saved me.
Round 3 was another LLD: classic Elevator system. Scheduling logic, multiple floor requests, direction algorithms, controller communicating with individual elevator objects. Standard if you've done LLD prep.
The AA round (Applied Problem Solving) was the most interesting. Three parts: write code to deliberately make a machine sluggish (I went the wrong direction initially - the actual angle was spreading CPU load across cores), pseudo-code for Google Docs LLD covering real-time collaboration and conflict handling, and a deep dive into my Rate Limiter project using the token bucket approach.
A few things worth noting
Interviewers across all rounds were collaborative. They care about how you think through a problem more than whether you immediately land the right answer. If you get redirected, don't panic - engage with it.
If you're prepping for L61 specifically, build something real from scratch. Having actual code you wrote makes the design rounds way more grounded. Happy to answer questions.