Description

The PHP layer has grown out of control since the start of the project and we have never taken time to review past engineering decisions that currently might not be necessary anymore. This means that we have a system that is slow, difficult to understand and maintainable, and very prone to bugs that are difficult to debug.

This issue is ultimately reflected in:

• Slow reaction time to bugs that can fully disable the system in production, as the fetch-instantiation-validaton cycle implemented in the middle layer comes into picture for every single request (view/edit pages, function call or perform test requests, etc.)
• Slower request response times, which directly affects the user experience.

Possibly related tasks:

• T362249: Drop support for creating a new ZPO inside the ZObjectFactory, if it is indeed unused
• Drop JSON-schema use in PHP
• T296724: WikiLambda: Remove validity of Z9 as value for a Z2K1 Removing schemata validation might involve solving this issue

Completion checklist

• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Front-end_Task/Bug_Completion_Checklist