Hadn't touched OOP in about a year, which showed a little at the start.
Start by clarifying requirements and constraints, then design a clean OOP interface for the core data structure with well-defined operations and complexity goals. Implement the initial version, test it, and then systematically address each follow-up extension by evaluating trade-offs and refactoring as needed.
Pro tip: Explicitly state your assumptions and ask clarifying questions before coding; interviewers value candidates who think before typing and adapt to new constraints gracefully.
Ask questions to understand the expected operations, input sizes, performance requirements, and any edge cases. Confirm the core functionality and what extensions might entail.
Define classes, methods, and relationships. Choose appropriate data structures and justify your choices based on time and space complexity. Sketch a UML diagram or write pseudocode.
Write clean, modular code for the initial design. Walk through examples and test edge cases to ensure correctness and efficiency.
For each extension, analyze how it impacts the design. Discuss necessary changes, potential trade-offs, and alternative approaches. Refactor code incrementally.
Recap the final design, highlighting key decisions, complexity analysis, and how you ensured extensibility. Mention any lessons learned or potential improvements.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.