Top 18 Essential .NET Libraries for Developers

Implementation Links for Each .NET Library

Find the implementation links for each library under the relevant headings.

1- Mediator

Use Case: Implements the CQRS pattern for separating read and write operations.

Pros: Simplifies code structure, and promotes single responsibility.

According to Microsoft Docs:

CQRS stands for Command and Query Responsibility Segregation, a pattern that separates read and update operations for a data store.

Learn more about design patterns in simple explanations e.g. Facade Pattern, Null Object Pattern, Adapter Design Pattern, Decorator Pattern, Service Locator Pattern, and Repository Design Patterns

2- Dapper

Use Case: A micro-ORM for mapping database results to objects.

Pros: Lightweight, easy to use.

Trivia: You can use Entity Framework when you need a full-featured ORM with advanced capabilities like change tracking and migrations. Dapper is my first choice when I have to write lengthy SQL queries with a lot of tables and complex joins.

3- Serilog

Use Case: Logging frameworks for simple and structured logging (Serilog)

Pros: Flexible, supports various sinks (40+ sinks)

Trivia: If you require a more traditional logging framework then use NLog.

4- Bogus

Use Case: Generates fake data for testing and development.

Pros: Easy to use, customizable data generation.

Trivia: For simple applications, I would prefer to create my custom bogus implementation instead of going for a library.

5- Fluent Validation

Use Case: Validates models in a fluent interface style.

Pros: Clear syntax, easy to maintain.

Trivia: Use Data Annotations for simpler validation needs where built-in attributes suffice.

6- Refit

Use Case: Simplifying HTTP API calls in .NET applications.

Pros: Reduces boilerplate code for making HTTP requests.

Trivia: Refit under the hood use HttpClient

7- Health Checks

Use Case: Monitoring the health of applications and services

Pros: Provides a standardized way to observe the status of services, it can be integrated with monitoring tools for alerts. Additionally, it helps ensure application reliability and availability.

8,9- Hangfire and Quartz

Use Case: Background job processing.

Pros: Reliable, easy to schedule jobs, and helpful in complex scenarios.

Trivia: Use Background Services for simple use cases.

10- Noda Time

Use Case: Advanced date and time handling.

Pros: Comprehensive, handles time zones well.

Trivia: Use System.DateTime for simpler applications where advanced date-time handling is not required. BTW Jon Skeet is the owner of the Noda Time library

11- Autofac

Use Case: Dependency Injection container.

Pros: Flexible, supports advanced scenarios.

Trivia: Use Microsoft.Extensions.DependencyInjection for simpler dependency injection needs.

12- MiniProfiler

Use Case: Speed profiling of applications.

Pros: Easy to integrate, provides detailed insights.

Trivia: Use Application Insights if you need more comprehensive monitoring.

13- Mapster

Use Case: Object-to-object mapping.

Pros: Reduces boilerplate code, and improves maintainability.

Trivia: There is a big debate about mappers and custom mapping, and I have covered a few questions :

14- NSubstitute

Use Case: Mocking framework for unit testing.

Pros: Easy to set up, supports complex scenarios.

Trivia: I was a big fan of Moq but I quit because they were quietly collecting users’ data

15- System.Text.Json

Use Case: JSON serialization/deserialization.

Pros: Mature, widely used, flexible, better performant

Trivia: NewtonSoft.Json is also a good option but I prefer System.Text.Json due to better performance.

16- BenchmarkDotNet

Use Case: Speed measurement of code.

Pros: Accurate, easy to use.

Trivia: It can be overkill for simple checks.

17- Swagger

Use Case: API documentation and testing.

Pros: Interactive documentation, easy to use.

Trivia: Use Postman Desktop Application, for API testing and documentation without the need for integrated solutions.

18- SignalR

Use Case: Real-time web functionality (e.g., chat applications).

Pros: Simplifies real-time communication, and supports various transports.

Use Web Sockets, if you need a more low-level approach to real-time communication without the overhead of a framework.