Start by clarifying requirements and scoping the file system (e.g., in-memory, basic operations, no persistence). Then design a clean interface and data structures, implement core operations, and write comprehensive tests covering normal and edge cases. Prioritize test-driven development to ensure correctness and demonstrate engineering rigor.
Pro tip: Write tests first to drive the design and catch edge cases early. Also, discuss trade-offs (e.g., using a tree vs. flat map) to show you think beyond just making it work.
Ask questions to define scope: in-memory or persistent? What operations (create, read, write, delete, list)? Any constraints on file size, path length, or concurrency? This shows you avoid assumptions.
Sketch the API (e.g., FileSystem class with methods) and choose data structures (e.g., tree of nodes for directories/files). Explain your choices and trade-offs.
Code the essential methods: create file/directory, write/read content, delete, list directory. Handle errors like invalid paths or name conflicts.
Develop test cases covering normal usage, edge cases (empty names, deep nesting, large files), and error conditions. Use a testing framework and ensure all tests pass.
Walk through your solution, highlighting design decisions, potential improvements (e.g., persistence, concurrency), and how you ensured test coverage.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.