What is compile-time polymorphism?

Short answer: Also called static polymorphism. Resolved at compile time. Achieved through method overloading or operator overloading. class Calculator

Example code

{
public int Add(int a, int b) => a + b;
public double Add(double a, double b) => a + b; // Overloaded method }

Real-world example (ShopNest)

Checkout calls IPaymentGateway.Charge(). Razorpay and Stripe adapters implement the same interface, so ShopNest can switch gateways without rewriting the order service.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.