I'm thinking of software running locally that's highly extensible, think VSCode and Chromium. Are there any in-depth guides on topics like allocating resources between extensions/plugins, managing permissions/sandboxing/security, loading and killing processes, enabling inter-extension communication, and so on?
What if they are not so extensible, but there is just too much money put in their development? These are some examples of the most complicated software ever built and never were just-for-fun projects. What you are asking is as operation system development with all well-know set of literature, starting probably from Tanenbaum.