[skore]

The frustrating thing is - the more you learn about what the OS can do, the more you realize that many programming languages and the applications written in them quite often reimplement large parts of the OS for an astonishingly large portion of their codebase. That isolates developers from learning about the OS in the first place. (They always end up needing to learn about it, anyhow, so it's a bit futile. Now, however, they feel smug about it and pretend like they shouldn't need to learn all this OS stuff.)

I guess developers always implement their own ignorance to a certain degree (and how could they not!? except, you know, spending more time learning their craft). What they don't know the OS can do, they will recreate - often poorly - in their own software. It does get rather comical and the various frameworks that you can subscribe to in modern programming languages repeat the concept, just that now, you're reimplementing things that the language can already do, but in the framework.

My favorite example is the various kinds of "service" patterns, like dependency injection - in many instances that I've seen, you could boil most of its use down to simple function calls. But since global functions are ew, you instead create a service that you inject and then call a method in. Boom, the gods of OOP are happy and nobody is allowed to say: "Wait a minute, if I take a few steps back and squint a little, what you're doing looks surprisingly similar to a global function call."

(And yes, I know, DI is supposed to be about overriding functions, yada yada very few people actually do that and it's often such an organizational hassle with downstream problems that projects eventually resort to put up conventions from doing that most of the time. Anyways - tell that to the people that I've seen implement, I kid you not, a CamelCaseService.)

[DaiPlusPlus]

DI services are usually abstracted behind interfaces - and most systems allow you to replace the service interface implementation at runtime.

So if you have a class that uploads files to a cloud storage provider - it would make use of IStorageProvider, and you might have AmazonS3StorageProvider, AzureBlobStorageProvider, LocalDiskStorageProvider, and for testing you would have DevNullStorageProvider.

A program using DI without interfaces with different implementations is missing the other advantages of DI.