dotnet/
├── ai/                    # ML.NET, ONNX, Azure AI, Microsoft.Extensions.AI, agents (A2A, MCP)
├── cli/                   # Spectre.Console, CliWrap, command-line cheatsheet
├── cloud/                 # Aspire, Azure Functions, Dapr, Orleans, service discovery
├── configuration/         # Extensions.Configuration, caching, feature flags, OpenFeature
├── data/                  # EF Core, Dapper, Redis, Lucene.NET, FluentStorage
├── dependency-injection/  # Extensions.DI, Generic Host, Spring.NET
├── documentation/         # OpenAPI / Swagger
├── eventing/              # MediatR, MassTransit, NServiceBus, Rebus, Wolverine, Brighter, Akka.NET
├── functional/            # F#, Language.Ext, FParsec, Optional, pidgin
├── general/               # Humanizer, ImageSharp, NodaTime, Stateless, worker services, cheatsheet
├── localization/          # i18n, resource-based localization, MessageFormat
├── logging/               # Serilog, NLog, Extensions.Logging
├── mapping/               # AutoMapper, Mapperly
├── networking/            # gRPC, DotNetty, MimeKit, System.IO.Pipelines, Twilio
├── observability/         # OTLP logging, OpenTelemetry conventions
├── project-system/        # MSBuild/csproj, Roslyn analyzers, source generators, EditorConfig, Fody
├── reactive/              # Rx.NET, System.Threading.Channels, DynamicData, IAsyncEnumerable
├── resilience/            # Polly, Extensions.Resilience
├── security/              # ASP.NET Identity, cryptography, authorization (Topaz, Enforcer)
├── serialization/         # Protobuf-net, Bond, Hyperion, FluentSerializer
├── testing/               # Testcontainers, Moq, AutoFixture, Pact, Reqnroll, Playwright
├── ui/                    # MAUI, Avalonia, Blazor, Uno Platform, Blazorise, MonoGame, Unity
├── validation/            # FluentValidation, Validot, Parse Don't Validate, CommunityToolkit.Guard
└── web/                   # ASP.NET Core, SignalR, YARP, Ocelot, GraphQL, Refit, Orchard CMS

// Global usings (C# 10) — reduce boilerplate across files
global using System.Text.Json;
global using Microsoft.Extensions.Logging;

// File-scoped namespaces (C# 10)
namespace MyApp.Services;

// Records with positional syntax — immutable data types
public record OrderPlaced(Guid OrderId, string CustomerId, decimal Total, DateTime PlacedAt);

// Primary constructors (C# 12) — DI without field ceremony
public class OrderService(IOrderRepository repo, ILogger<OrderService> logger)
{
    public async Task<Order> GetAsync(Guid id)
    {
        logger.LogInformation("Fetching order {OrderId}", id);
        return await repo.FindAsync(id) ?? throw new NotFoundException(id);
    }
}

// Collection expressions (C# 12)
int[] numbers = [1, 2, 3, 4, 5];
List<string> names = ["Alice", "Bob", "Charlie"];
ReadOnlySpan<byte> header = [0x48, 0x54, 0x54, 0x50];

// Pattern matching with list patterns (C# 11)
string Describe(int[] values) => values switch
{
    [] => "empty",
    [var single] => $"one item: {single}",
    [var first, .., var last] => $"from {first} to {last}",
};

// Raw string literals (C# 11) — no escaping needed
var json = """
    {
        "name": "Widget",
        "price": 29.99,
        "tags": ["electronics", "sale"]
    }
    """;

// Required members (C# 11)
public class Config
{
    public required string ConnectionString { get; init; }
    public required int MaxRetries { get; init; }
    public TimeSpan Timeout { get; init; } = TimeSpan.FromSeconds(30);
}

// Switch expressions with property patterns
decimal CalculateDiscount(Order order) => order switch
{
    { Total: > 1000, Customer.IsPremium: true } => order.Total * 0.15m,
    { Total: > 500 } => order.Total * 0.10m,
    { Customer.IsPremium: true } => order.Total * 0.05m,
    _ => 0m,
};