One of the checklist items in the product department's playbook is:
Use MediaWiki best practices and engineering architecture principles for frontend and backend development.
So, in this task, let's scan https://www.mediawiki.org/wiki/Wikimedia_Engineering_Architecture_Principles and see if there are any things we missed in the Image-Suggestions project. If there are issues, we can file follow-up tasks for them.
Extra effort would be to also double-check https://www.mediawiki.org/wiki/Best_practices_for_extensions while we're at it.