Microsoft·Software Engineer·Onsite - Coding / Algorithms
Jun 2026
Microsoft SWE coding round, no AI tools allowed. Had to implement a SingleFlight component to handle burst traffic in front of an LLM service, and my code didn't compile by the end which I'm pretty sure tanked the whole thing.
- Design and implement a SingleFlight component that sits in front of an LLM service to batch or deduplicate burst traffic. Then analyze the edge cases your implementation handles.
“The core idea is straightforward enough: if ten requests come in for the same key at the same time, only one should actually hit the backend and the rest should wait and share the result.” The rest of the author's notes on Software Engineer interview at Microsoft, Onsite - Coding / Algorithms round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.
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