How Netflix uses Java

created or ported? I thought it was created elsewhere.

I never hated Spring, I got used to working with it. I found the annotation-based approach to configuring classes really opaque though, and it was hard to understand how to configure things because those were also magic annotations, and then some things were beans and others weren't and... ugh.

I don't fault Spring for it, and we were on Java 11 back then with just a little bit of new hotness. Java itself just didn't lend itself to the best ergonomics.

And you could fault Ruby or any dynamic language for the same, but they usually save you a little bit of overhead or boilerplate.

I assume they mean problems with dependency injection.

If that's what they mean, I agree. I've seen dependency injection frameworks used in a bunch of different companies, and there are always people who consider it an essential lifesaver, like they just can't imagine working without it, and it always baffles me, because I've worked on equally large codebases that didn't use it, and it was occasionally a significant annoyance to pass dependencies by hand, but never equal to the annoyance of dealing with an automatic dependency injection framework.

This repeated experience of working with and without dependency injection, finding dependency injection to be at least as much hassle as it saves, and seeing that the people I've worked with who choose dependency injection have massively warped impressions of what it's like to work without it (they often think it's, like, impossible) has led me to see it as a tool that is driven mostly by FUD, at least at the scale of code that I have worked with.

And that's without even considering the deleterious effect that dependency injection has on design. In my cynical moments I think this is the real reason people love dependency injection. It's not that people hate the five minutes it takes to figure out how to manually pass a dependency to a module; it's that they hate the subconscious thinking that happens in those five minutes, as they see how the change affects the code, and it dawns on them that it's a code smell for every module to depend on everything else. Sometimes a dependency is a code smell, and dependency injection means you barely get a whiff, so faint you can pretend it's just your imagination. Doing it by hand means you get a few minutes to bask in the stench. You can't pretend you didn't notice.

Getting people to care about modularity, coupling, and cohesiveness in an application with dependency injection is markedly harder, just like it's harder in a language with global variables, just like it's harder to get people to think about APIs and modularity in a monolith than in microservices. And for me that's the worst part of working on codebases with pervasive dependency injection! Dependency injection is a massive liberating force for people who want to work without thinking about design. Instead of thinking about it, they just add another spaghetti dependency and keep on going, and do the same thing tomorrow, and the next day, and the next day. It's impossible to stop them! Adding a dependency is so immediate, so easy, there's no moment where they have to stop and think, "Hmmm, why am I using a dependency in module A that was only ever used in module B before? I'll need to instantiate it at the application level instead. But that means I need to pull some internal logic out of B so it can be run before B exists. Should I really be doing this? I'd better think/ask about this before I do it." Instead they just add an annotation and see if the dependency injection framework can figure it out. That's the only kind of problem I can think of that dependency injection excels at solving: problems that should never have been solved in the first place.

> Why would framework be correct if the premise of heavy runtime reflection based approach itself is bad?

Because the framework allows zero reflection approach.

This is absolutely spot-on. The concepts that Johnson & co coalesced around, mainly IoC, DI, interfaces, and layers, are bedrock foundations for how most people write any service-oriented system. Say what you want about the things that Boot itself does, like auto configuration, or the Data persistence abstractions, but the foundations of the library are bedrock software engineering, so if you're gonna dump on something that's proven over 20+ years, you better come correct.

This "lingua franca" of Java development also allows you to hire, onboard, and get people productive - rapidly.