How does polymorphism help in loose coupling?
Answer: Code depends on interfaces or base classes, not concrete implementations. Makes system flexible, extendable, and easier to maintain. void StartVehicle(Vehicle v) { v.Start(); } // Works with any derived type
What interviewers expect
- A clear definition tied to OOP in C# OOP projects
- Trade-offs (performance, maintainability, security, cost)
- When you would and would not use it in production
Real-world example
In a production C# OOP application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.
How to explain in the interview
- Define the concept in one or two sentences.
- Context — where it fits in C# OOP architecture.
- Example — a specific project, bug, or performance win.
- Trade-off — what you gain vs what you sacrifice.
Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.