Identify and mitigate deduplication program risks
Company: Anthropic
Role: Software Engineer
Category: System Design
Difficulty: hard
Interview Round: Technical Screen
What problems can a file deduplication program encounter in real-world use, and how would you mitigate them? Discuss permission and I/O errors, files changing during the scan (TOCTOU), path length limits, symlink loops, memory and disk bottlenecks, hash function choice and collision risks, partial vs. full hashing verification, concurrency and throttling, incremental rescans and checkpointing, and safe dedupe actions (e.g., verifying before deletion or replacing with hard links). Provide concrete strategies for each.
Overview: This question evaluates understanding of system design and practical engineering competencies required for building resilient file deduplication tools, covering filesystem semantics, error handling, hashing and collision considerations, concurrency, performance bottlenecks, cross-platform interoperability, and safety trade-offs.