Find Duplicate Files + Follow-ups on Optimization and Distributed Systems

Given a collection of files (abstracted as paths plus content/metadata), find and output groups of duplicate files. The base coding task is to detect duplicates. Follow-ups discuss/design: time/space optimization (e.g., bucket by size/metadata, then hash, then byte-by-byte compare when needed); scaling in a distributed system (partitioning, dedup keys, skew handling, fault tolerance, idempotency, and consistency). Note: The write-up does not specify the exact definition of "duplicate", I/O format, or constraints (number/size of files, memory limits), so a fully codable statement cannot be reconstructed; the theme is retained.