Interview Q&A

Short answer: public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; }

Example code

public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; } public virtual Category Category { get; set; }

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: SignalR vs WebSockets Feature WebSockets SignalR Protocol Low-level TCP-based High-level abstraction Transpor Only WebSockets Fallbacks: WebSockets → SSE → Long Polling Usage Real-time messages Real-time hubs with automatic reconnection, grouping, scaling ✅ Use SignalR for apps needing broadcast, connection management, and fallbacks.

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 Host in Azure App Service? Answer: Azure App Service provides PaaS hosting for ASP.NET Core apps. Steps: Publish the app via Visual Studio, CLI, or GitHub Actions. dotnet publish -c Release Create App Service in Azure portal. Deploy using FTP, Git, or CI/CD pipelines. App Service automatically configures Kestrel + reverse proxy. ✅ Supports scaling, HTTPS, and monitoring out-of-the-box.

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: pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health"); pp.MapHealthChecks("/health");

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: Role-based authorization restricts access based on user roles. ssign a role: wait _userManager.AddToRoleAsync(user, "Admin"); Use in controllers: [Authorize(Roles = "Admin")] public IActionResult Dashboard() => View(); You can also combine roles: [Authorize(Roles = "Admin,Manager")] 🧭 7. {

Example code

public int Age { get; }
public MinimumAgeRequirement(int age) => Age = age;
}
public class MinimumAgeHandler : uthorizationHandler<MinimumAgeRequirement> { protected override Task HandleRequirementAsync( uthorizationHandlerContext context, MinimumAgeRequirement requirement) {
var birthDateClaim = context.User.FindFirst(c => c.Type == "BirthDate"); if (birthDateClaim != null)
{
var birthDate = DateTime.Parse(birthDateClaim.Value);
if (birthDate.AddYears(requirement.Age) <= DateTime.Today) context.Succeed(requirement); }
return Task.CompletedTask;
}
} Register it: builder.Services.AddAuthorization(options => { options.AddPolicy("AdultOnly", policy => policy.Requirements.Add(new MinimumAgeRequirement(18))); }); builder.Services.AddSingleton<IAuthorizationHandler, MinimumAgeHandler>(); Use it: [Authorize(Policy = "AdultOnly")] public IActionResult BuyAlcohol() => Ok("Access granted"); 🍪 9. What is cookie authentication in ASP.NET Core? Cookie authentication stores user information in an encrypted cookie on the browser. When the user revisits, the cookie is used to identify them. Configure: builder.Services.AddAuthentication(CookieAuthenticationDefaults.Auth enticationScheme) .AddCookie(options => {
options.LoginPath = "/Account/Login";

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: Claims-based authentication is based on claims — pieces of information about the user (like email, role, or permissions).

Explain a bit more

Each user has a collection of claims represented as key-value pairs.

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: pp.UseExceptionHandler("/Home/Error"); or public class GlobalExceptionFilter : IExceptionFilter { public void OnException(ExceptionContext context) { context.Result = new ViewResult { ViewName = "Error" }; } } 🧩 19.

Explain a bit more

pp.UseExceptionHandler("/Home/Error"); or public class GlobalExceptionFilter : IExceptionFilter { public void OnException(ExceptionContext context) { context.Result = new ViewResult { ViewName = "Error" }; } } 🧩 19. {

Example code

public void OnException(ExceptionContext context)
{
context.Result = new ViewResult { ViewName = "Error" };
}
} 🧩 19. How to return partial views? Partial views are used to render reusable page sections (like headers, sidebars). Example: public IActionResult ProductList()
{
var products = _service.GetAll();
return PartialView("_ProductListPartial", products);
} In Razor: @Html.Partial("_ProductListPartial", Model.Products) 🧾 20. Explain Razor Pages vs MVC. Feature Razor Pages MVC Structure Page-based (.cshtml + .cshtml.cs) Controller + View Best For Simple or CRUD pages Complex or large web apps URL /Products/Edit → /Pages/Products/Edit.cshtml /Products/Edit → ProductController.Edit() Code Location In the same file (PageModel) Separate Controller class Example: Razor Pages are like simplified MVC without controllers — great for admin dashboards or forms. Dependency Injection (DI)

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: builder.Services.AddHealthChecks(); app.MapHealthChecks("/health"); builder.Services.AddHealthChecks(); app.MapHealthChecks("/health"); builder.Services.AddHealthChecks(); app.MapHealthChecks("/health"); builder.Services.AddHealthChecks(); app.MapHealthChecks("/health");

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: 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 9⃣ How to Monitor Performance and Uptime?

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: TestContainers spins up real Docker containers (SQL Server, Redis) for integration testing, simulating production.

Explain a bit more

using Testcontainers.MsSql; var sqlContainer = new MsSqlBuilder() .WithPassword("yourStrong(!)Password") .Build(); wait sqlContainer.StartAsync(); var options = new DbContextOptionsBuilder<AppDbContext>() .UseSqlServer(sqlContainer.GetConnectionString()) .Options; // Use context in tests ✅ Benefits: Real database behavior CI/CD friendly Close to production setup Deployment & Hosting How to Deploy an ASP.NET Core App to IIS? TestContainers spins up real Docker containers (SQL Server, Redis) for integration testing, simulating production.

Example code

using Testcontainers.MsSql; var sqlContainer = new MsSqlBuilder() .WithPassword("yourStrong(!)Password") .Build(); wait sqlContainer.StartAsync(); var options = new DbContextOptionsBuilder<AppDbContext>() .UseSqlServer(sqlContainer.GetConnectionString()) .Options; // Use context in tests ✅ Benefits: Real database behavior CI/CD friendly Close to production setup Deployment & Hosting How to Deploy an ASP.NET Core App to IIS? TestContainers spins up real Docker containers (SQL Server, Redis) for integration testing, simulating production. Example: using Testcontainers.MsSql; var sqlContainer = new MsSqlBuilder() .WithPassword("yourStrong(!)Password") .Build(); wait sqlContainer.StartAsync(); var options = new DbContextOptionsBuilder<AppDbContext>() .UseSqlServer(sqlContainer.GetConnectionString()) .Options; // Use context in tests ✅ Benefits: Real database behavior CI/CD friendly Close to production setup Deployment & Hosting How to Deploy an ASP.NET Core App to IIS? IIS (Internet Information Services) can host ASP.NET Core apps via the ASP.NET Core Module, which forwards requests to Kestrel. Steps: TestContainers spins up real Docker containers (SQL Server, Redis) for integration testing, simulating production. Example: using Testcontainers.MsSql; var sqlContainer = new MsSqlBuilder() .WithPassword("yourStrong(!)Password") .Build(); wait sqlContainer.StartAsync(); var options = new DbContextOptionsBuilder<AppDbContext>() .UseSqlServer(sqlContainer.GetConnectionString()) .Options; // Use context in tests ✅ Benefits: Real database behavior CI/CD friendly Close to production setup Deployment & Hosting How to Deploy an ASP.NET Core App to IIS? IIS (Internet Information Services) can host ASP.NET Core apps via the ASP.NET Core Module, which forwards requests to Kestrel. Steps:

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: Claims-based authentication is based on claims — pieces of information about the user (like email, role, or permissions).

Explain a bit more

Each user has a collection of claims represented as key-value pairs.

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: Partial views are used to render reusable page sections (like headers, sidebars). public IActionResult ProductList() var products = _service.GetAll(); return PartialView("_ProductListPartial", products); In Razor: Follow : @Html.Partial("_ProductListPartial", Model.Products) 🧾 20. Partial views are used to render reusable page sections (like headers, sidebars).

Example code

public IActionResult ProductList() var products = _service.GetAll(); return PartialView("_ProductListPartial", products); In Razor: Follow : @Html.Partial("_ProductListPartial", Model.Products) 🧾 20. Partial views are used to render reusable page sections (like headers, sidebars). Example: public IActionResult ProductList() var products = _service.GetAll(); return PartialView("_ProductListPartial", products); In Razor: Follow : @Html.Partial("_ProductListPartial", Model.Products) 🧾 20. Explain Razor Pages vs MVC. Feature Razor Pages MVC Structure Page-based (.cshtml + .cshtml.cs) Controller + View Best For Simple or CRUD pages Complex or large web apps URL /Products/Edit → /Pages/Products/Edit.cshtml /Products/Edit → ProductController.Edit() Code Location In the same file (PageModel) Separate Controller class Example: Razor Pages are like simplified MVC without controllers — great for admin dashboards or forms. Dependency Injection (DI) Partial views are used to render reusable page sections (like headers, sidebars). Example: public IActionResult ProductList() var products = _service.GetAll(); return PartialView("_ProductListPartial", products); In Razor: Follow : @Html.Partial("_ProductListPartial", Model.Products) 🧾 20. Explain Razor Pages vs MVC. Feature Razor Pages MVC Structure Page-based (.cshtml + .cshtml.cs) Controller + View Best For Simple or CRUD pages Complex or large web apps URL /Products/Edit → /Pages/Products/Edit.cshtml /Products/Edit → ProductController.Edit() Code Location In the same file (PageModel) Separate Controller class Example: Razor Pages are like simplified MVC without controllers — great for admin dashboards or forms. Dependency Injection (DI)

Real-world example (ShopNest)

ShopNest’s product edit form posts to an MVC action. Model binding fills a ProductEditVm; the action validates and redisplay the view on errors.

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: Using SignalR for Real-Time Communication // Hub public class ChatHub : Hub { public async Task SendMessage(string user, string message) => await Clients.All.SendAsync("ReceiveMessage", user, message); } // Client (JavaScript) const connection = new signalR.HubConnectionBuilder() .withUrl("/chathub") .build(); connection.on("ReceiveMessage", (user, message) => { console.log(`${user}: ${message}`); }); await…

Explain a bit more

connection.start(); await connection.invoke("SendMessage", "Alice", "Hello!");

Example code

Using SignalR for Real-Time Communication // Hub public class ChatHub : Hub
{
public async Task SendMessage(string user, string message) =>
await Clients.All.SendAsync("ReceiveMessage", user, message); } // Client (JavaScript) const connection = new signalR.HubConnectionBuilder() .withUrl("/chathub") .build(); connection.on("ReceiveMessage", (user, message) => { console.log(`${user}: ${message}`); }); await connection.start();
await connection.invoke("SendMessage", "Alice", "Hello!");

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: Response caching caches the entire HTTP response at the server level — useful for static or rarely changing API responses.

Explain a bit more

Setup: builder.Services.AddResponseCaching(); var app = builder.Build(); pp.UseResponseCaching(); Controller Example: [ResponseCache(Duration = 60, Location = ResponseCacheLocation.Any)] [HttpGet] public IActionResult GetTime() => Ok(DateTime.Now); ✅ The response is cached for 60 seconds — subsequent requests are served faster. {

Example code

return Ok(new { Category = category, Time = DateTime.Now });
} ✅ Benefits: Works with authenticated users. Supports vary-by parameters, headers, and policies. Integrates well with minimal APIs and Razor pages. 🗜 7. How to compress responses? Use response compression middleware to reduce payload size for clients. Setup: builder.Services.AddResponseCompression(options => {
{
var data = await _service.GetDataAsync(); // Non-blocking call
return Ok(data);
} ✅ Benefits: Frees threads while waiting for I/O (e.g., DB, HTTP calls). Improves scalability and throughput. Essential for high-traffic APIs and cloud-native apps. ❌ Avoid Task.Result or .Wait() — they block threads and reduce performance. ⚡ 9. How to optimize startup performance? To improve startup and cold-boot performance: ✅ Tips:

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: zure App Service PaaS Easy scaling, HTTPS CI/CD GitHub Actions / Azure DevOps Automated build/test/deploy Logging ILogger, Serilog, NLog Use structured logging Monitoring Application Insights, Prometheus Track metrics, uptime Health Checks ASP.NET Core HealthChecks Expose /health endpoints This gives a complete production-ready workflow from… deployment… to…… monitoring.

Explain a bit more

zure App Service PaaS Easy scaling, HTTPS CI/CD GitHub Actions / Azure DevOps Automated build/test/deploy Logging ILogger, Serilog, NLog Use structured logging Monitoring Application Insights, Prometheus Track metrics, uptime Health Checks ASP.NET Core HealthChecks Expose /health endpoints This gives a complete production-ready workflow from deployment to… monitoring. dvanced & Modern Topics Middleware Pipeline in Depth ASP.NET Core handles HTTP requests through a middleware pipeline, which is a sequence of components where each can: Inspect or modify the request Call the next middleware Short-circuit the pipeline Pipeline Flow: Request -> Middleware1 -> Middleware2 ->…… {

Example code

public async Task SendMessage(string user, string message) => wait Clients.All.SendAsync("ReceiveMessage", user, message); } // Client (JavaScript) const connection = new signalR.HubConnectionBuilder() .withUrl("/chathub") .build(); connection.on("ReceiveMessage", (user, message) => { console.log(`${user}: ${message}`); }); wait connection.start(); wait connection.invoke("SendMessage", "Alice", "Hello!"); 5⃣ Background Services (IHostedService) For long-running tasks or scheduled jobs Implement IHostedService or extend BackgroundService public class TimedWorker : BackgroundService
{ protected override async Task ExecuteAsync(CancellationToken stoppingToken) { while (!stoppingToken.IsCancellationRequested) { Console.WriteLine("Running background task"); wait Task.Delay(10000, stoppingToken); }
}
} builder.Services.AddHostedService<TimedWorker>(); ✅ Good for periodic jobs, email processing, queue consumers. 6⃣ Hangfire or Quartz.NET for Background Jobs Hangfire Example: pp.UseHangfireDashboard(); RecurringJob.AddOrUpdate(() => Console.WriteLine("Recurring job"), Cron.Daily); Quartz.NET: Supports cron-like scheduling and clustered execution. 7⃣ Health Checking in ASP.NET Core builder.Services.AddHealthChecks() .AddSqlServer(connectionString) .AddCheck<CustomHealthCheck>("CustomCheck"); pp.MapHealthChecks("/health"); Custom Health Check Example: public class CustomHealthCheck : IHealthCheck
{
public Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken token) => Task.FromResult(HealthCheckResult.Healthy("Everything OK")); } 8⃣ 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 })); }); pp.UseRateLimiter(); ✅ Helps protect APIs from abuse or DoS attacks. 9⃣ DataAnnotations for Validation public class Product
{ [Required] public string Name { get; set; } [Range(1, 100)] public decimal Price { get; set; }
} Works with model binding Automatic client & server-side validation with Razor or API endpoints 🔟 Global Exception Logging pp.UseExceptionHandler(errorApp => { errorApp.Run(async context => {

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: Docker allows running ASP.NET Core apps in containers, portable across environments. Dockerfile Example: # Build stage FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build WORKDIR /app COPY *.csproj ./ RUN dotnet restore COPY .

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: public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); } } Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15.

Explain a bit more

How do you pass data from controller to view?

Example code

public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); } } Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); } } Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); } } Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); } } Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use: public class LogActionFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext context) { Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); }
} Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use:

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: Docker allows running ASP.NET Core apps in containers, portable across environments. Dockerfile Example: # Build stage FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build WORKDIR /app COPY *.csproj ./ RUN dotnet restore COPY .

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: Configuration providers are components that load configuration data from various sources.

Explain a bit more

Built-in Providers: JSON files (appsettings.json) Environment variables Command-line arguments In-memory collections Azure Key Vault User Secrets (for local dev) Custom providers (you can build your own) builder.Configuration .AddJsonFile("appsettings.json") .AddEnvironmentVariables() .AddCommandLine(args); Each provider plugs into the same configuration system, so you can access everything via IConfiguration. Configuration providers are components that load configuration data from various sources. Built-in Providers: JSON files (appsettings.json) Environment variables Command-line arguments In-memory collections Azure Key Vault User Secrets (for local dev) Custom providers (you can build your own)

Example code

builder.Configuration .AddJsonFile("appsettings.json") .AddEnvironmentVariables() .AddCommandLine(args); Each provider plugs into the same configuration system, so you can access everything via IConfiguration. Configuration providers are components that load configuration data from various sources. Built-in Providers: JSON files (appsettings.json) Environment variables Command-line arguments In-memory collections Azure Key Vault User Secrets (for local dev) Custom providers (you can build your own) Example: builder.Configuration .AddJsonFile("appsettings.json") .AddEnvironmentVariables() .AddCommandLine(args); Each provider plugs into the same configuration system, so you can access everything via IConfiguration. Configuration providers are components that load configuration data from various sources. Built-in Providers: JSON files (appsettings.json) Environment variables Command-line arguments In-memory collections Azure Key Vault User Secrets (for local dev) Custom providers (you can build your own) Example: builder.Configuration .AddJsonFile("appsettings.json") .AddEnvironmentVariables() .AddCommandLine(args); Each provider plugs into the same configuration system, so you can access everything via IConfiguration. 🔐 3. How do you manage secrets in development? In development, never store passwords, API keys, or connection strings in code or ppsettings.json. Use User Secrets — a safe way to store secrets outside the project tree. 🧰 4. What is User Secrets in ASP.NET Core? User Secrets are a local, developer-only configuration storage that keeps sensitive data out of source control. Setup: Enable secrets: dotnet user-secrets init

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: public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15.

Explain a bit more

How do you pass data from controller to view?

Example code

public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use: public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use: public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use: public class LogActionFilter : ActionFilterAttribute public override void OnActionExecuting(ActionExecutingContext context) Console.WriteLine($"Action: {context.ActionDescriptor.DisplayName}"); Use it: [LogActionFilter] public IActionResult Index() => View(); 📤 15. How do you pass data from controller to view? You can use:

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: Hangfire or Quartz.NET for Background Jobs Hangfire

Example code

app.UseHangfireDashboard(); RecurringJob.AddOrUpdate(() => Console.WriteLine("Recurring job"), Cron.Daily); Quartz.NET: Supports cron-like scheduling and clustered execution.

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 Test Minimal APIs? Answer: Minimal APIs are tested using WebApplicationFactory or TestServer. Example: var factory = new WebApplicationFactory<Program>();

Example code

var client = factory.CreateClient();
var response = await client.GetAsync("/products");
var products = await response.Content.ReadFromJsonAsync<List<Product>>(); Assert.NotEmpty(products);

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: Health Checking in ASP.NET Core builder.Services.AddHealthChecks() .AddSqlServer(connectionString) .AddCheck<CustomHealthCheck>("CustomCheck"); app.MapHealthChecks("/health"); Custom Health Check Example: public class CustomHealthCheck : IHealthCheck

Example code

{
public Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken token) => Task.FromResult(HealthCheckResult.Healthy("Everything OK")); }

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 Serilog or NLog? Serilog Example (Program.cs): builder.Host.UseSerilog((ctx, lc) => lc .WriteTo.Console() .WriteTo.File("logs/log-.txt", rollingInterval: RollingInterval.Day) ); NLog

Example code

Install NLog.Extensions.Logging package Add NLog.config file Configure in Program.cs: builder.Logging.ClearProviders(); builder.Logging.SetMinimumLevel(LogLevel.Information); builder.Host.UseNLog(); ✅ Both support structured logging, sinks, filtering, and rolling files.

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: What Frameworks Are Commonly Used? Answer: xUnit – Popular, lightweight, supports parallel testing. NUnit – Rich assertion library. MSTest – Microsoft-supported, integrated in Visual Studio. Most modern ASP.NET Core projects use xUnit + Moq.

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.