InversifyJS VS Nest

Vorarbeiter Service Container is about 10 times lighter then InversifyJS. It has simpler API and works faster.

One of the most popular libraries in JavaScript for implementing the Inversion of Control (IoC) pattern is InversifyJS. It provides a robust and flexible framework for managing dependencies in a clean, modular way. However, InversifyJS has some drawbacks. One major limitation is the amount of boilerplate code required to set up and manage dependencies. Additionally, it often requires structuring your application in a specific way, which may not suit every project.

Take a class for which we are tasked to write a unit test. This class may have a dozen methods and a dozen more attributes. In my environment we were already using inversify to dependency inject into this class, and using container snapshot and restore as setup and teardown operators, in our jest test file. But it began getting out of control even after refactoring into test cases and test runners.

Inversify (https://inversify.io/) for IoC.

Alguns frameworks trabalham desta forma por padrão, como é o caso do Angular, quando este não é o padrão do framework que utilizamos podemos usar alguma biblioteca, como a Inversify ou tsyringe da Microsoft.

Using decorators required setting an --experimentalDecorators experimental compiler flag. Several popular TypeScript libraries, such as type-graphql and inversify, rely on this implementation.

inversify

start the app (we use NestJS with fastify)

Coming from a background in large-scale Java systems with Spring Boot, I’ve learned to appreciate the value of a well-structured framework. NestJS brings that same level of organization and scalability to the TypeScript ecosystem, something often undervalued when choosing a backend framework.

Often, developers opt for a framework when building out APIs, as they offer alternative means of representing resources, and many tools and utilities designed to make this process easier. One such example is NestJS (Not to be confused with Next.js!). This is a batteries-included, powerful "framework for building efficient, scalable Node.js server-side applications". Heavily inspired by Angular, this framework allows developers to use abstractions to represent API routes, including reusable services, controllers, modules and more.

NestJS is a progressive Node.js framework inspired by Angular's architecture. It uses TypeScript and follows object-oriented programming principles, making it ideal for building scalable server-side applications. Its modular structure encourages the separation of concerns, leading to more maintainable code. (Check out Nest)

Read more about Next.js here and Nest.js here.

NestJS GitHub Repository

In this article, we will walk through a step-by-step process to secure a Nest.js RESTful API using Keycloak. This includes setting up an application client and configuring authentication and RBAC for your API endpoints.

The rapid evolution of web development in 2025 makes it imperative to choose a framework that truly fits your project. Whether this involves a dynamic web application, scalable API, or high-performance SaaS product, the decision to select Next.js or Nest.js becomes all the more key. While both do their thing really well, in this sense, they don't do the same thing.

nest.js