How do you apply the Strategy pattern to select different caching strategies in .NET?

Short answer: Define a caching interface: public interface ICacheStrategy { void Cache(string key, object value); object Retrieve(string key); } Implement strategies like MemoryCacheStrategy, DistributedCacheStrategy. Use DI or factory to inject the chosen strategy at runtime: public class CacheContext

Example code

{
private readonly ICacheStrategy _cacheStrategy;
public CacheContext(ICacheStrategy cacheStrategy)
{
_cacheStrategy = cacheStrategy;
}
public void Cache(string key, object value) => _cacheStrategy.Cache(key, value); } This enables switching caching mechanisms without code changes.

Real-world example (ShopNest)

ShopNest payment fees use Strategy: IFeeCalculator with UPI/Card implementations chosen at runtime.

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.