Interview Q&A

Short answer: ASP.NET Core Data Protection API provides secure cryptographic APIs for: Encrypting cookies and tokens Protecting form data Persisting secure keys (across app restarts) Setup: builder.Services.AddDataProtection() .PersistKeysToFileSystem(new DirectoryInfo(@"c:\keys")) .SetApplicationName("MyApp"); You can use it directly: var protector =………… _provider.CreateProtector("MyPurpose"); var encrypted =…

Explain a bit more

protector.Protect("secret-data"); var decrypted = protector.Unprotect(encrypted); ✅ Data Protection is the backbone for: Cookie Authentication CSRF Tokens TempData encryption 🧠 Summary Concept Description Best For In-memory caching Stores data in server memory Single-server or dev Distributed caching Shared cache (Redis, SQL) Scalable apps Response caching Caches HTTP responses Public/static data Output caching (.NET 8) Advanced, user-aware caching Dynamic APIs Response compression Gzip/Brotli for responses Large payloads sync/await Non-blocking I/O High concurrency Startup optimization Faster app boot Cloud apps… ASP.NET Core Data…… var encrypted = protector.Protect("secret-data");

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.

Short answer: ASP.NET Core Data Protection API provides secure cryptographic APIs for: Encrypting cookies and tokens Protecting form data Persisting secure keys (across app restarts) Setup: builder.Services.AddDataProtection() .PersistKeysToFileSystem(new DirectoryInfo(@"c:\keys")) .SetApplicationName("MyApp"); You can use it directly: var protector =………… _provider.CreateProtector("MyPurpose"); var encrypted =…

Explain a bit more

protector.Protect("secret-data"); var decrypted = protector.Unprotect(encrypted); ✅ Data Protection is the backbone for: Cookie Authentication CSRF Tokens TempData encryption 🧠 Summary Concept Description Best For In-memory caching Stores data in server memory Single-server or dev Distributed caching Shared cache (Redis, SQL) Scalable apps Response caching Caches HTTP responses Public/static data Follow : Output caching (.NET 8) Advanced, user-aware caching Dynamic APIs Response compression Gzip/Brotli for responses Large payloads Async/await Non-blocking I/O High concurrency Startup optimization Faster app boot… ASP.NET Core Data……

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.

Short answer: Compiled queries improve performance by caching query translation.

Example code

private static readonly Func<AppDbContext, decimal, IEnumerable<Product>> _getExpensiveProducts = EF.CompileQuery((AppDbContext ctx, decimal price) => ctx.Products.Where(p => p.Price > price)); var result = _getExpensiveProducts(_context, 1000); 🔍 19. Pool Size=5; uthentication & Authorization

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.

Short answer: Rate Limiting Middleware in .NET 8 builder.Services.AddRateLimiter(options => { options.GlobalLimiter = PartitionedRateLimiter.Create<HttpContext, string>(httpContext => RateLimitPartition.GetFixedWindowLimiter(httpContext.Connection.Remo teIpAddress?.ToString()!, _ => new FixedWindowRateLimiterOptions { PermitLimit = 10, Window = TimeSpan.FromMinutes(1), QueueLimit = 2 })); }); app.UseRateLimiter(); ✅ Helps protect…

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.

Short answer: How to Enable Application Insights? Answer: Application Insights provides monitoring, telemetry, and tracing. Setup: builder.Services.AddApplicationInsightsTelemetry(builder.Configurati on["APPINSIGHTS_INSTRUMENTATIONKEY"]); Features: Track requests, exceptions, and dependencies Live metrics and dashboards Custom events and telemetry

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.

Short answer: How to Use Moq for Mocking Dependencies? Answer: Moq creates fake implementations of interfaces to control behavior during tests. Example: var mockRepo = new Mock<IProductRepository>(); mockRepo.Setup(x => x.GetAll()).Returns(new List<Product> { new Product { Id = 1, Name = "Laptop" } });

Example code

var service = new ProductService(mockRepo.Object);
var products = service.GetAll(); Assert.Single(products); ✅ Use .Setup(), .Verify(), and .Returns() to simulate behavior.

Real-world example (ShopNest)

ShopNest admin screens use MVC: controller loads data, Razor view renders HTML, Tag Helpers build forms safely.

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.