Why you should become a .NET Developer

C# and .NET have been around long enough to prove they're not a trend. They run on Windows, macOS, and Linux, power everything from APIs to desktop apps to games, and the tooling is friendly even when you're new. If you've been thinking about picking up a language that can take you from "Hello, World" to full products without switching stacks every week, this is a solid bet.

This post gives you a quick tour of what C#/.NET looks like today (latest SDK), what you can build in your first month, and a couple of tiny code samples to get you moving.

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Why C# right now

• One stack, many targets. Build web APIs (ASP.NET Core), desktop/mobile apps (.NET MAUI), command-line tools, services, and games (Unity uses C# for scripting).
• Cross-platform from the start. Install the SDK once and use the same CLI on Windows, macOS, or Linux.
• Modern language features. Records, pattern matching, async/await, spans, source generators—C# keeps gaining practical features without turning into a puzzle.
• NuGet for packages. Pull in libraries with a single command and keep your project tidy.
• Great editors. Visual Studio, VS Code, Rider—pick your flavor.

You don’t need a giant setup to begin. The dotnet CLI and a text editor will carry you very far.

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What you can build in your first month

• Week 1 — Basics: types, methods, collections, LINQ, async/await. Write small console tools.
• Week 2 — Web API: Minimal APIs with routing, JSON, and validation.
• Week 3 — Data: talk to a database with EF Core; learn migrations and simple queries.
• Week 4 — UI or services: pick MAUI for a small desktop/mobile app or deepen your API with authentication and caching.

Along the way, add unit tests so you trust your changes.

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Your first Minimal API (15 lines)

Create and run a tiny API:

dotnet new web -n HelloApi
cd HelloApi
dotnet run

Open Program.cs and add two endpoints:

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "API is up");

app.MapGet("/hello/{name}", (string name) =>
    Results.Json(new { message = $"Hello, {name}" }));

app.Run();

You now have a running HTTP server. Hit http://localhost:5000/hello/Nick and you’ll get a JSON response.

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Language tour in one minute

C# reads well and has a few small features that save a lot of code.

Records (immutable data with value equality):

public sealed record Customer(string Id, string Email);

Pattern matching (clear branching without nested ifs):

static decimal DiscountFor(int items) => items switch
{
    <= 0   => 0m,
    1 or 2 => 0.05m,
    <= 10  => 0.10m,
    _      => 0.15m
};

Async/await (non-blocking I/O):

using var http = new HttpClient();
var json = await http.GetStringAsync("https://example.com/data");
// continue without blocking a thread

LINQ (expressive collection queries):

var top = orders
    .Where(o => o.Total > 100)
    .OrderByDescending(o => o.CreatedAt)
    .Take(5)
    .Select(o => new { o.Id, o.Total });

You can write clear, compact code without clever tricks.

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A slightly bigger example: a tiny catalog API

Let’s combine a few ideas—Minimal API, validation, and a simple in-memory store (later you can swap for EF Core).

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

var items = new Dictionary<Guid, CatalogItem>();

app.MapPost("/items", (CreateItem req) =>
{
    if (string.IsNullOrWhiteSpace(req.Name)) return Results.BadRequest("Name is required");
    if (req.Price < 0) return Results.BadRequest("Price must be >= 0");

    var item = new CatalogItem(Guid.NewGuid(), req.Name.Trim(), req.Price);
    items[item.Id] = item;
    return Results.Created($"/items/{item.Id}", item);
});

app.MapGet("/items/{id:guid}", (Guid id) =>
    items.TryGetValue(id, out var item) ? Results.Ok(item) : Results.NotFound());

app.MapGet("/items", () => items.Values);

app.Run();

public sealed record CreateItem(string Name, decimal Price);
public sealed record CatalogItem(Guid Id, string Name, decimal Price);

This style scales surprisingly well. When the logic grows, move it into plain classes and keep the endpoints thin.

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Tooling: the basics you’ll actually use

• dotnet new — create projects (web, console, classlib, xunit, mstest).
• dotnet add package — install libraries from NuGet.
• dotnet run / dotnet test / dotnet build — daily commands you’ll memorize in a day.
• Editors — VS Code plus the C# extension is a great cross-platform setup. Visual Studio (Windows) gives you powerful designers and profilers.

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Testing from day one

Unit tests keep you honest as your code grows. Here’s a quick example with xUnit and Shouldly (license-friendly).

dotnet new xunit -n GettingStarted.Tests
dotnet add GettingStarted.Tests package Shouldly

using Shouldly;

public class DiscountTests
{
    [Theory]
    [InlineData(0, 0)]
    [InlineData(2, 0.05)]
    [InlineData(5, 0.10)]
    [InlineData(50, 0.15)]
    public void Calculates_expected_discount(int items, decimal expected)
        => DiscountFor(items).ShouldBe(expected);

    static decimal DiscountFor(int items) => items switch
    {
        <= 0   => 0m,
        1 or 2 => 0.05m,
        <= 10  => 0.10m,
        _      => 0.15m
    };
}

Run dotnet test and you get instant feedback.

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Where C# shows up in real projects

• Web — fast APIs with ASP.NET Core, JSON handling built in, middleware pipeline, filters, and validation libraries.
• Desktop & Mobile — .NET MAUI lets you share code across platforms while still producing native apps.
• Games — Unity uses C# for gameplay code, tooling, and editor scripts.
• Tools & Services — background jobs, CLI utilities, automation scripts.

It’s common to see teams ship an API, a small admin tool, and a scheduled worker—all in C#—which keeps hiring and maintenance simple.

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A simple learning path (no fluff)

1. Install the SDK and confirm with dotnet --info.
2. Console basics: variables, methods, classes, List<T>, LINQ. Write a small CSV parser or a file renamer.
3. Minimal APIs: routes, model binding, error handling, configuration.
4. Data: EF Core with a local database, basic CRUD, migrations.
5. Testing: xUnit + Shouldly; aim for one test per rule.
6. Refine: split logic into services, return problem details on errors, add validation.

Stick to this and you’ll avoid a lot of pain.

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Common early mistakes (and how to dodge them)

• Putting all logic in endpoints. Move logic into plain classes so you can test it without HTTP.
• Tight coupling to DateTime.UtcNow, random, or GUIDs. Abstract them behind interfaces so tests can control time and IDs.
• Big “god” projects. Split your app into modules or projects early (API, Application, Infrastructure). It pays off fast.
• Skipping tests “for later.” Write small tests for the rules that matter. They take minutes and save hours.