Under the hood, Nest makes use of robust HTTP Server frameworks like Express (the default) and optionally can be configured to use Fastify as well!
Nest provides a level of abstraction above these common Node.js frameworks (Express/Fastify), but also exposes their APIs directly to the developer. This allows developers the freedom to use the myriad of third–party modules which are available for the underlying platform.
Nest provides an out–of–the–box application architecture which allows developers and teams to create highly testable, scalable, loosely coupled, and easily maintainable applications. The architecture is heavily inspired by Angular.
Specification: Develop RESTful Web Services using NestJS and MongoDB