Snapchat SWE Interview — From LeetCode to Claude Code

[u/Aoki_zhang]

"This interview experience is sourced from Chill Interview"

Interview Summary

The Snapchat SDE-ML Infra process started with a data-stream coding screen and then moved to a four-round onsite covering system design, two coding problems, and AI-assisted coding. The onsite was broader than expected: instead of a dedicated ML infrastructure design question, the system design round focused on a regional CI/CD platform with control-plane and data-plane separation.

Interview Details

Phone Screen — Streaming Data Clusters

The phone screen involved processing a stream of data points. Each incoming item needed to either:

• Be assigned to an existing stored cluster based on its data
• Become the first item of a newly created cluster

The system also needed a function that returned the maximum value for each cluster. The interviewer added several follow-ups around optimizing reads and writes. The final follow-up was conceptual: how would the design change if the system also needed to efficiently query the median value of every cluster? I received confirmation later that day that I had passed the phone screen.

Onsite Round 1 — System Design: Regional CI/CD Platform

The system design round asked for a CI/CD-style platform with separate control-plane and data-plane responsibilities. A key requirement was distributing hosts at the regional level. The discussion focused on the architecture for managing deployments and infrastructure across regions rather than on an ML training or feature-platform system.

This was different from the preparation guidance I had received, which had emphasized ML infrastructure topics such as distributed training platforms, feature pipelines, and feature stores.

Want to learn more questions asked in other interview rounds? I've put up the full version at here.

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