Spent the first few minutes just listing out what I assumed the requirements were before actually asking for clarification.
Start by clarifying the password requirements and constraints with the interviewer, then outline a modular design that separates validation rules from the core checker. Implement the checker using efficient string operations and discuss trade-offs between different approaches, such as regex versus manual parsing.
Pro tip: Demonstrate awareness of security best practices by mentioning that password validation should be part of a broader security strategy, including hashing and salting, and avoid storing plaintext passwords. Also, consider edge cases like Unicode characters and performance for large-scale systems.
Ask questions to understand the specific password requirements (e.g., length, character types, special characters) and any constraints like performance or memory. Confirm whether the checker should be a function or a class and if it needs to be extensible.
Propose a modular design where each requirement is a separate validation rule, possibly using the Strategy pattern. Discuss how to combine rules and handle errors, and choose appropriate data structures for efficiency.
Write clean, efficient code that checks each rule, using built-in string methods or regex as appropriate. Handle edge cases like empty strings, null inputs, and Unicode characters, and ensure the code is readable and maintainable.
Walk through test cases covering valid and invalid passwords, including boundary conditions (e.g., exactly minimum length, missing one character type). Discuss how to unit test each rule and the overall checker.
Talk about trade-offs between regex and manual checks (e.g., readability vs. performance), and how to extend the checker for new requirements. Mention security considerations like not logging passwords and using constant-time comparisons if relevant.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.