There's quite fundamental optimizations that will be missing if separately compiled pieces cannot optimize together. These barriers disallow many things. Additi

There's quite fundamental optimizations that will be missing if separately compiled pieces cannot optimize together. These barriers disallow many things. Additionally, anything that relies on higher order functions provided by the user, such as optimization or differential equations, will run into issues because those functions cannot be optimized by some super good package developer, but instead have to come from the user. This blog post highlights the massive performance advantages Julia can have when you start integrating optimized packages and allow for optimizing across these barriers in Julia, and also the pros and cons of allowing these kinds of cross-function optimizations. https://www.stochasticlifestyle.com/why-numba-and-cython-are-not-substitutes-for-julia/ https://www.stochasticlifestyle.com/why-numba-and-cython-are...