Microsoft interview notes, page 12 of 60

FAANG / Big Tech

Most of these Microsoft write-ups come from Software Engineers (372), then Product Managers (124) and Machine Learning Engineers (53). The most reported rounds are the technical phone screen (255), the product sense round (111), the system design round (93) and the behavioral / leadership round (49).

597 interview notes · updated Oct 2026

Microsoft·Software Engineer·Technical Phone Screen

Apr 2026

Microsoft SWE interview with a tree traversal follow-up that only one candidate in the session even got to. Ran out of time before finding out if there were more questions after it, which was a little unsettling.

Given a table representing a company hierarchy (where each manager record includes a list of their direct reports), write a function to find all reports under a given person at any depth.

“Went with BFS, which felt right for level-by-level traversal of a tree structure.”

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Microsoft·Software Engineer·Technical Phone Screen

Apr 2026

Microsoft SWE interview that came down to a classic LRU cache problem. Not the hardest thing on paper, but the O(1) constraint plus the follow-up discussion on implementation details made it more involved than I expected.

Design an LRU cache data structure with get and put operations, both running in O(1) average time. Walk through how you'd implement it.

“I knew the answer going in but fumbled the explanation of why you need both a hashmap and a doubly-linked list.”

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Microsoft·Software Engineer·Technical Phone Screen

Apr 2026

Microsoft SWE interview, pretty straightforward. One coding problem and then a Q&A at the end. Nothing too wild but the coding part had a small wrinkle worth noting.

Given a list of numbers and an integer k, return the list with only the top k largest values kept and everything smaller removed.

“Classic top-k problem.”

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Microsoft·Software Engineer·Technical Phone Screen

Apr 2026

Microsoft SWE interview with a graph traversal problem that's basically a TSP variant. Pretty classic bitmask DP territory if you recognize what it is, which is the whole challenge.

Given a weighted graph, a starting node, and a set of required nodes, find the minimum total distance for a tour that starts at the origin, visits all required nodes at least once, and returns to the origin.

“The second I saw 'visit all required nodes and return to start' I knew it was TSP-flavored but blanked on the exact DP formulation for a bit.”

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Microsoft·Data Scientist·Technical Phone Screen

Apr 2026

Got a probability question at Microsoft that looked straightforward but required you to actually know Bayes' theorem cold. Not a coding round, felt more like a stats/analytical screen.

Two machines produce light bulbs: Machine A makes 60% of total output with a 5% defect rate, Machine B makes the rest with a 3% defect rate. A randomly chosen bulb turns out to be defective. What's the probability it came from Machine A?

“I knew this was a conditional probability setup but blanked on the exact formula for a second.”

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Microsoft·Data Scientist·Recruiter / HR Screen

Apr 2026

Interviewing for a Data Scientist role at Microsoft, and the scheduling alone has been a whole ordeal. Two reschedules, one last-minute cancellation, and now a third attempt that already feels shaky.

How would you respond to repeated last-minute interview reschedules while keeping the process moving and staying professional?
What specific guardrails would you put in place to protect your time when working with a company that has shown poor scheduling reliability?
How would you negotiate time-zone windows and minimize disruption when a company keeps moving your interview slot?
If a third interview attempt also fails, what is your escalation path and at what point would you pause or withdraw from the process entirely?
What do repeated scheduling failures signal about a company's culture and operational maturity, and how would you factor that into your decision to continue?

“This one is less about technical chops and more about reading the room.”

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Microsoft·Data Scientist·Technical Phone Screen

Apr 2026

Interviewed at Microsoft for a data science or ML-adjacent role, got hit with a classic regression question that felt straightforward but had more to it than I expected.

What are the advantages and limitations of linear regression?

“I rattled off the advantages fine, interpretability, computational efficiency, works well when the relationship is actually linear.”

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Microsoft·Software Engineer·Technical Phone Screen

Apr 2026

Microsoft software engineer round covering conceptual topics across threading, memory layout, OOP, and distributed systems design. Nothing hands-on, just talking through ideas, which I actually preferred but still stumbled on a few parts.

What is a mutex and why would you need one in a multithreaded app where threads share a counter and a shared object?
What kinds of bugs show up when you update shared data from multiple threads without synchronization?
How does a mutex compare to a read-write lock or a semaphore?
What is memory alignment, and how does field ordering inside a struct affect memory usage due to padding?
Walk through reordering struct fields to reduce memory usage, and explain why poor memory layout can hurt cache performance.
Explain compile-time versus run-time polymorphism with examples, and give a concrete class hierarchy that shows how polymorphism improves extensibility.
What does it mean for an operation to be idempotent, and why does it matter for retries and distributed systems?

“Felt fine explaining the concept but then they asked me to walk through actually using it to protect the counter and I got a bit hand-wavy.”

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Microsoft·Product Manager·Onsite - Product Sense / Strategy

Apr 2026

Interviewed at Microsoft for a product role and got a meaty marketplace strategy question. Pretty open-ended, which I wasn't fully prepared for.

How would you design an apps marketplace for Microsoft Office Suite? Walk through the key considerations, and what are the tradeoffs involved.

“I spent the first minute just trying to figure out where to even start.”

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Microsoft·Software Engineer·Onsite - System Design / Architecture

Apr 2026

System design round at Microsoft for a software engineering role. The whole session was basically one big deep-dive into payment infrastructure, which sounds focused but actually means you need to cover a lot of ground fast.

Design a payment processing system that handles user-initiated payments at scale, supporting cards, ACH, and digital wallets.
How would you handle idempotency so that a retried payment request doesn't result in a double charge?
Walk through how you'd design the async settlement pipeline and handle retries and dead-letter queues.
How would you approach sharding the ledger to support high throughput while maintaining strong consistency?
How would you minimize PCI scope in the system's architecture?
How would you integrate fraud and risk scoring into the payment authorization flow without adding significant latency?

“I started with the API surface and worked inward, which felt right in the moment but I skipped over the ledger design for too long and the interviewer had to nudge me toward it.”

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