Part of the overengineering in J2EE comes from essentially trying to make one app server be multitenant instead of just spinning up one process per tenant.

That this came from a company essentially selling mini computers.

In fact, we are trying to do multi-tenant all over again. To my mind, this cycle of containerization is still trying to fulfill all the promises we were given in the early 90's about memory protected, pre-emptive multitasking OSes that never came true. Which itself wasn't the first time (it's all copying mainframe ideas, badly). Given all of the problems coming out about speculative execution and data breaches, I'm already curious what the next set of promises will look like.