Julia is definitely trickier to control because it's an extremely powerful language. After all you can write even programs that can rewrite itself in it (like Cassette/Zygote, which is more than simply AST manipulation but full IR manipulation), there is no limit to how clever your program can be. But that level of introspection in the future could bring amazing linter capability to the language, that could detect all kind of bad practices as you type (for example type piracy, type instabilities, and possibly enforce customizable policies) which will become important tools as more people aim to use the language in production environments.

And until then the best practices for larger project using Julia's paradigm (Multiple Dispatch, which is by itself not as well understood as OOP or functional) will probably become more largely known. I feel like Julia projects should not grow large not because it's not suitable for large scale projects, but because even large scale Julia projects should emerge from the composition of many small and maintainable Julia projects.