One of the best practices for micro frontends is to clearly define the boundaries between them. This is important to avoid conflicts and ensure that each microfrontend can be developed independently.

By defining clear boundaries, each microfrontend can have its own codebase, dependencies, and build process. This allows teams to work on different parts of the application without interfering with each other.

Shared API Layer: One way to define boundaries is to use a shared API layer. This layer acts as a contract between microfrontends, defining the data and functionality that each microfrontend can access. This allows each microfrontend to be developed independently, without worrying about the implementation details of other microfrontends. For example, if one microfrontend needs to display a list of products, it can make a request to the API layer for the necessary data. The API layer can then retrieve the data from the backend and return it to the microfrontend in a standardized format. This approach allows each microfrontend to focus on its own functionality, while still being able to communicate with other microfrontends when necessary.

Web components: Another way to define boundaries is to use web components. Web components are a set of standardized APIs that allow developers to create reusable components that can be used across different frameworks and applications. By using web components, microfrontends can be developed independently and then combined into a larger application. This approach allows each microfrontend to be developed using the framework or library that is best suited for its needs, while still being able to work together seamlessly. For example, one microfrontend could be developed using React, while another could be developed using Angular. Both microfrontends could then be combined into a larger application using web components.