Seemed easy and I almost wrote a one-liner without thinking.
Start by clarifying requirements and edge cases, then propose a clean solution using Python's built-in methods like str.lower() and str.count(). Discuss time and space complexity, and consider alternative approaches for different scenarios.
Pro tip: Mention that you'd use str.casefold() instead of str.lower() for more robust case-insensitive comparison, especially for Unicode characters. Also, note that if the character is not a single character, you should handle it appropriately.
Ask about input constraints: is the character always a single character? Should the function handle Unicode? What about empty strings? This shows attention to detail.
Explain that you'll convert both the string and the character to lowercase (or casefold) and then count occurrences. Alternatively, iterate through the string and compare each character case-insensitively.
Implement the function using Python's built-in methods for simplicity and efficiency, e.g., return string.lower().count(char.lower()).
State that the time complexity is O(n) where n is the length of the string, and space complexity is O(n) due to creating a lowercased copy (or O(1) if iterating without extra space).
Mention testing with empty string, character not present, uppercase/lowercase mix, and non-ASCII characters if relevant.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.