nestjs is a progressive Node.js framework for building efficient and scalable server-side applications. It leverages TypeScript and incorporates elements from object-oriented programming, functional programming, and reactive programming. NestJS is particularly well-suited for building enterprise-grade applications and microservices, providing a robust architecture that promotes maintainability and scalability. Its modular structure allows developers to organize their code effectively, making it easier to manage large codebases.

While NestJS offers a comprehensive solution for server-side development, there are several alternatives that developers can consider:

• express is one of the most popular web application frameworks for Node.js. It provides a minimal and flexible set of features for building web applications and APIs. Express is known for its simplicity and ease of use, making it a great choice for small to medium-sized applications. Its middleware architecture allows developers to add functionality to their applications easily. If you are looking for a lightweight framework that allows for quick development and flexibility, Express is an excellent option.
• fastify is a fast and low-overhead web framework for Node.js that is designed for building high-performance applications. It emphasizes speed and efficiency, making it a great choice for applications that require high throughput. Fastify provides a powerful plugin architecture, allowing developers to extend its functionality easily. If performance is a key concern for your application, Fastify is worth considering due to its focus on speed and low resource consumption.
• koa is another web framework for Node.js created by the same team behind Express. Koa is designed to be a smaller, more expressive, and more robust foundation for web applications and APIs. It uses async/await syntax, which makes it easier to write and manage asynchronous code. Koa's middleware system is also more powerful and flexible compared to Express, allowing for better control over the request and response cycle. If you prefer a more modern approach to building web applications and want to leverage async/await, Koa is an excellent choice.

To see how these frameworks compare, check out the comparison: Comparing express vs fastify vs koa.