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For web developers, Node.js provides an attractive backend platform that is widely used in various scenarios, from building simple APIs to supporting high concurrency microservice systems, thanks to its event driven and non blocking features.

However, as the business develops, you will gradually discover a problem:

Projects of different scales have vastly different requirements for frameworks and architectures.

Using native HTTP modules or Express for small projects is fast and flexible enough

Medium sized projects are beginning to face issues such as chaotic routing, coupled business logic, and difficulty in testing

Enterprise level projects require modular architecture, dependency injection, automated testing support, and even microservice decoupling capabilities

NestJS, as an enterprise level Node.js framework built on TypeScript, was born to address these issues.

This article will help you gradually establish a system understanding and practical skills for backend development through a progressive process, starting from native HTTP, Express, and then NestJS.

1、 Build a server using the native HTTP module of Node.js

The HTTP module that comes with Node.js can quickly start a server, which is very suitable for beginners to understand the underlying principles:

The advantage of the native HTTP module is that it is quick to learn and does not require additional dependencies, making it particularly suitable for learning HTTP request and response mechanisms. However, it also has some obvious drawbacks, such as the need to manually handle routing and status codes, lack of support for middleware mechanisms, and easy code bloating. With the expansion of functionality, the original structure becomes difficult to organize complex business logic, making the project difficult to maintain. Therefore, although native modules are powerful, they are not suitable as long-term solutions in practical development.

II Express

Express abstracts the tedious details of underlying HTTP, brings middleware mechanisms and clear routing definitions, greatly improving development efficiency. Express makes it easy and feasible to write backend using JavaScript, thus ushering in the golden age of Node.js as a server-side technology stack.

Express has a concise API (such as app. get, app. post) and middleware mechanism, making logical splitting simple. At the same time, it also has a rich ecosystem and a large number of supporting plugins, making it very suitable for rapid MVP development. However, it lacks a unified architectural specification, which can easily lead to code confusion in large projects. Due to the lack of a native dependency injection mechanism, the coupling between services is high, and the organizational structure of controllers, services, and routers is often manually agreed upon, making it difficult to standardize collaboration. When you want to build a rigorous and maintainable backend system, Express often seems inadequate.

III Koa

Koa.js (released in 2013) was created by the original team of Express and is known as the "spiritual successor of Express". It was born to solve the confusion problem of Express in middleware chain processing, while natively supporting asynchronous/await, making asynchronous processes clearer and more elegant. Compared to Express, Koa is more pure in the application of modern JavaScript features and provides the possibility to build more concise and maintainable services.

The biggest advantage of Koa is the adoption of the onion model middleware mechanism, which makes the middleware process clearer and more controllable, greatly improving the maintainability of the code. It only retains the most basic functions, while others such as routing and body parsing are provided in the form of plugins, enhancing flexibility and composability. At the same time, Koa natively supports asynchronous/await, making asynchronous logic more elegant, and the overall design is closer to the native HTTP interface of Node.js.

But the disadvantage is that it is relatively difficult to get started with and not very beginner friendly; Due to the plugin based functionality, developers need to manually assemble commonly used capabilities, resulting in slightly higher initial setup costs. In addition, the community ecology and documentation are slightly weaker compared to Express, which may not be ideal for projects that pursue out of the box use

4 fastify

Fastify (released in 2017) was initiated by Matteo Collina, a core contributor to Node.js, with the goal of building a "super fast, plugin based, type safe" next-generation Node.js web framework. Its emergence is to compensate for the insufficient performance of Express in high concurrency scenarios, while addressing the pain points of lack of type inference and built-in schema validation support. In contrast, Fastify provides more refined configurable capabilities in logging, serialization, route matching, and other aspects, making it more suitable for building modern, high-performance backend services.

Fastify has excellent performance, being 2-4 times faster than Express in HTTP/1 scenarios, with a processing capacity of over 65000 simple requests per second, far exceeding Koa and Express. This is due to its highly optimized serialization process at the underlying level.

It natively supports asynchronous/await and implements request validation, type inference, and automatic generation of OpenAPI documents through JSON Schema, greatly improving development efficiency and type safety.

In addition, Fastify has a powerful plugin system that can integrate almost all functional modules on demand, supporting modern development needs such as TypeScript, Swagger, logging, JWT, etc., truly achieving a balance between high performance and high scalability.

5、 Building Enterprise Projects with NestJS: Structuring is the King

With the popularity of Node.js in enterprise development, traditional frameworks such as Express, although flexible and easy to use, lack architectural specifications, modular capabilities, and type safety support, making it difficult to support complex projects. Although Koa, Fastify, and others have improved in performance and control, they still lean towards "tool based frameworks" and require developers to organize their own project structures. The emergence of NestJS is to address this pain point - it combines Angular style modular architecture, dependency injection (DI) mechanism, and strongly typed TypeScript support, providing a complete development paradigm for large, maintainable, and testable server-side applications. In short, NestJS is an architectural solution designed for enterprise level Node.js projects.

This structure clearly distinguishes between the request entry point (Controller) and the business logic (Service), and when combined with modules for organization, large-scale projects can also be organized in an orderly manner. This is the true essence of spring.js.

NestJS provides a clear modular architecture that enables hierarchical organization of controllers, services, and business logic, facilitating team collaboration and code maintenance. It has a built-in dependency injection mechanism (DI), which improves the testability and decoupling ability of the code. Built on TypeScript, NestJS has strong typing support and modern development experience. At the same time, it natively supports advanced features such as middleware, guards, interceptors, etc., and can flexibly respond to various business needs. More importantly, it has strong scalability and can seamlessly integrate modern backend technology stacks such as microservices, GraphQL, and WebSocket.

summary

In the evolution of backend development in Node.js, the native HTTP module laid the foundation for communication at the lowest level, but it has low development efficiency and lacks structure, making it only suitable for teaching and understanding principles.

Express, as the earliest popular web framework, quickly became the de facto standard with its concise routing and middleware mechanism, suitable for small and medium-sized projects and rapid development.

Koa is a refactoring attempt by the Express team, introducing asynchronous/await and onion model middleware to make asynchronous processing more elegant and control more flexible.

Fastify focuses on performance optimization, with excellent throughput capabilities and plugin design, making it an ideal choice for high concurrency interfaces and microservice gateways.

NestJS builds a complete enterprise level architecture based on these frameworks, providing features such as modularity, dependency injection, type safety, and test friendliness, making it particularly suitable for medium to large projects and multi team collaborative development. Overall, these frameworks have their own strengths, ranging from lightweight and fast to structurally clear. Developers can choose the most suitable tool based on project size and complexity.