#filesystems

5 filesystems interview questions, asked at Anthropic, OpenAI, Applied Intuition and 6 more companies. Last asked Sep 2026.

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Crash-safe on-disk key-value storeCodingBuild a filesystem-backed hash table that survives crashes and restores every entry from the latest state on restart. Reported on 1point3acres' Baseten bank; reconstructed in our…
Last asked Sep 2026
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Deduplicate files by size then content hashCodingWalk a directory tree and group files with identical content. Compare file sizes first so large files are hashed only when sizes collide, then hash the rest. Be ready to discuss…
Last asked Sep 2026
Repository Merkle tree hashing and change detectionCodingHash a code repository into a Merkle tree over files and directories so changed paths are found by comparing hashes top-down instead of rescanning everything. Reported on…
Last asked Sep 2026
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Split a file iterator into balanced line-aligned partsCodingSplit a large file into balanced parts for parallel workers without cutting lines in half: each part holds whole lines and the parts stay close in size. Reported on 1point3acres'…
Last asked Sep 2026
Simplified filesystem with paths and traversalCodingImplement a small filesystem with path lookup and directory traversal, extended in the final level with model-related behavior. The harness is strict, so edge cases around paths…
Last asked May 2026