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The hardest part wasn't the implementation, it was just reading the skeleton fast enough to understand what each TODO actually needed.
Start by thoroughly understanding the abstract base classes and their contracts, then map out the concrete subclasses and their required implementations. Implement each subclass method one by one, ensuring they satisfy the abstract methods and integrate correctly with the rest of the system. Test incrementally to verify end-to-end functionality without modifying public interfaces or base classes.
Pro tip: Before writing any code, write a quick test or script that exercises the system end-to-end to identify exactly which methods are missing and how they should behave. This prevents guesswork and ensures you only implement what's necessary.
Read through each ABC and its abstract methods to understand the required interface and expected behavior. Note any docstrings, type hints, or comments that specify contracts.
Locate all concrete subclasses that inherit from the ABCs and determine which abstract methods they have not yet implemented. Use tools like grep or IDE inspections to find unimplemented methods.
For each missing method, write an implementation that adheres to the base class contract and integrates with existing code. Ensure you do not modify the base classes or public interfaces.
Run the system or write integration tests to verify that the implementations work together correctly. Debug and refine as needed, ensuring all abstract methods are implemented and the system functions as expected.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
They asked me to walk through my process out loud.
Start by explaining your systematic process for understanding the skeleton: mapping the abstract methods to their call sites and the overall control flow. Then describe how you used that map to decide where to add logic, emphasizing how you validated your changes to avoid unintended side effects. Highlight the trade-offs you considered, such as minimal invasiveness versus clarity.
Pro tip: Mention that you often add temporary logging or use a debugger to trace the actual runtime flow, which reveals the intended extension points and catches subtle dependencies that static reading might miss. This shows you combine code analysis with empirical verification.
Read the entire skeleton to identify the main components, abstract methods, and their relationships. Pay attention to comments, method names, and any documentation that hint at intended extension points.
Find where each abstract method is called and trace the execution path from entry points. Use tools like call hierarchy or grep to see all usages, which clarifies which methods are meant to be overridden and where.
Determine which abstract methods are designed for subclass implementation versus which are internal. Look for patterns like template method or strategy to infer the intended places for logic.
Write a small test or use a debugger to confirm your understanding. This helps verify that your intended changes are in the right place and don't break existing behavior.
Make changes incrementally, running tests after each step. Review the diff to ensure you haven't modified unrelated parts, and consider if your changes align with the original design.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Blanked for a second on where validation should live.
Start by explaining the problem context and why separating parsing, validation, and execution is important for maintainability and testability. Then describe how you used composition to delegate each responsibility to dedicated components within the concrete classes, and discuss the trade-offs and benefits you observed.
Pro tip: Emphasize that separation of concerns via composition makes unit testing easier because you can mock or stub each component independently, and it adheres to the Single Responsibility Principle, which is highly valued at Bloomberg.
Briefly describe the system or feature where you implemented this separation, and the challenges that motivated it.
Detail how you identified parsing, validation, and execution as distinct responsibilities and decided to encapsulate each in its own class or interface.
Explain how the concrete classes are composed of these components, e.g., by injecting parser, validator, and executor dependencies, and how they interact.
Discuss the advantages such as improved testability, flexibility, and maintainability, and any trade-offs like increased number of classes or indirection.
Conclude with the impact: easier debugging, faster feature additions, or better team collaboration, and any lessons learned.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Start by clarifying the classes and their responsibilities, then outline a testing strategy that combines unit tests for individual classes with integration tests for key interactions. Use a testing framework like JUnit (or pytest) and demonstrate how you would mock dependencies to isolate units and verify behavior.
Pro tip: Focus on testing behavior and contracts rather than implementation details; this makes tests resilient to refactoring and aligns with Bloomberg's emphasis on maintainable, high-quality code.
List all implemented classes and map out their key interactions, including method calls and data flow between them.
For each class, outline unit tests covering normal behavior, edge cases, and error conditions, ensuring each public method is tested.
Select critical interaction paths between classes and design tests that verify the combined behavior, using real objects or minimal mocks.
Decide on a testing framework (e.g., JUnit, Mockito) and techniques like mocking, stubbing, and dependency injection to isolate units.
Implement the tests with clear naming, arrange-act-assert structure, and organize them into suites for unit and integration tests.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.