I do know what you mean, but the Elixir ecosystem is fairly exceptional in this regard. (It helps that Elixir is a compiled language with macros; many libraries

I do know what you mean, but the Elixir ecosystem is fairly exceptional in this regard. (It helps that Elixir is a compiled language with macros; many libraries implement optional-dep support via the compile-time-macro equivalent of the strategy pattern, where you only get the runtime code you ask for, rather than a bunch of useless calls to hooks that have no subscribers in your codebase. And if you're imagining that results in awful codegen code, it doesn't; in many cases, this is just as simple as putting an if statement directly into a module body, with method definitions inside the if branches.) It's also helped by an eye toward low coupling of these support libraries. Elixir's Phoenix web framework, for example, is "batteries included" in some senses; but all those batteries are only included because your own generated skeleton code pulls them in; not because the framework itself depends on them in any way. So if you don't need e.g. i18n, or views, or really anything beyond an API that responds with JSON; then you can delete ~five lines from your skeleton project, drop the relevant deps, and the resulting project will be a lightweight web framework that just serves API calls. (This is why there isn't really a "lightweight" Elixir web framework ala Flask/Sinatra/etc.; Phoenix is both Elixir's batteries-included web framework, and its lightweight/minimal web framework, depending on how you use it.)