Put each class into its own file without side-effects

[szepeviktor]

What you think about that?
Something similar to PSR-4.

[beaulebens]

What would that end up looking like?

And why would we be doing it? (what are you aiming to accomplish?)

[szepeviktor]

What would that end up looking like?

Like a Composer package.

And why would we be doing it? (what are you aiming to accomplish?)

PSR-4 is beneficial. For example would enable simple and predictable autoloading.
Namespace and class name structure would be the same as the file structure.
e.g. Keyring\Service\Fitbit would live in src/Service/Fitbit.php

Basically leaving legacy technologies behind. E.g. wave goodbye to require statements.

BTW You may be interested in the results of this research: https://github.com/szepeviktor/small-project/blob/master/MAIN-FILE-PARTS.md

[szepeviktor]

Annotation based hooking is like a paradigm shift for us WordPress people.

    /**
     * @hook wp_insert_post 1000
     */
    public function onInsertPost(int $postId, WP_Post $post, bool $update): void