Stage 1 — Must-Know C# and ASP.NET Core Fundamentals

Predict the behavior of value types, reference types, boxing, nullability, equality, and parameter passing in short C# examples.

Critique and improve a small C# object model using encapsulation, polymorphism, interfaces, composition over inappropriate inheritance, and dependency inversion.

Choose an appropriate generic collection for lookup, uniqueness, ordering, queueing, or thread-safe access.

Explain how delegates, lambdas, and events support callbacks and decoupled behavior in C#.

Predict when a LINQ query executes and distinguish filtering, projection, materialization, and multiple enumeration.

Trace how Task, async, and await affect control flow, exceptions, and concurrency in a short C# operation.

Explain constructor injection and trace how the ASP.NET Core dependency-injection container resolves an object graph.

Trace an ASP.NET Core request through middleware, routing, model binding, validation, an endpoint, and the response.