Implement tag matcher and filesystem

This interview reportedly included two coding problems:

1. Tag matching in text Given a sentence and a list of tags or keywords, return the tags that appear in the sentence as whole-word matches. Matching may be treated as case-insensitive, but partial-word matches do not count. For example, if the sentence contains blueprint, the tag blue must not be considered a match. Be prepared to clarify how punctuation, duplicates, and output ordering should be handled.

2. In-memory file system Design and implement an in-memory file system that supports common operations such as:

• creating directories,
• listing directory contents,
• writing file contents,
• reading file contents.

Be prepared to discuss path parsing, internal data structures, and edge cases such as nested directories, creating missing parents, and appending to an existing file.