[revskill]

Yes, we have a term for that: Technical debts!

The reality is like this: You have a critical system that ran for ages, and now what will you do to scale the features ? By allowing/teaching junior devs to understand how to contribute to the codebase ?

There's a simpler way to do that efficiently: Extract a subdomain into its own microservice and you control the interface. Then even that microservice has bad code quality (tech debt), your business is still running fine!

Problem solved.