PHP Symfony How To Make CMS Modular

I’m new to Symfony, I’ve been experimenting with the framework and I kind of like it.
My goal is to create a CMS that is modular (extensible).

The core should contain stuff such as:

  • User management
  • Routes
  • Pages (articles)
  • Media

Modules (extensions) could be e.g.:

  • Products
  • References
  • Distributors
  • Newsletters

I’ve been reading about hexagonal architecture lately, and it seems like a good idea to take this path. Although you can find several example projects on GitHub and other places, they are were simplified.
I haven’t seen any Symfony CMS using this architecture where I could take inspiration from.

Sylius takes the advantage of bundles, is it a good way to go?

Basically, I would want to achieve the following:

  • The core should be decoupled from modules
  • Modules should be able to communicate between one another
  • It would be nice to be able to fix bugs or add new features to the core or modules without breaking everything

Could an experienced Symfony developer give me a piece of advice on the “best” approach?