At this point the only thing I can say is. Have you ever been a Julia user? Or are you actively developing Julia? If you are actively developing Julia, yea sure pull down the feature branch after someone's reported a bug, hot fix your toml to point too some specific version after reading ten diffs to be sure you have the right one, maybe stand up your own package server or pay 50k for one from julia computing, recompile Julia itself and everything is totally fine! If it's not no big deal just stomp over the type with your own code, yay. Maybe that's even part of your job. If you're a user expecting to do development and receive updates on packages or language, all I'll say is best of luck.
I run in production several Julia projects and I honestly can't say I know what you are referring to.
I do use some libraries through PyCall. This is a relatively frequent source of trouble, with libraries breaking because of 3rd party dependencies, behaviour changing, or even somehow installation suddenly stops working. This all happens in the python side, to the point that I am currently replacing all the libraries even if it means porting some of them or even a loss of functionality.
You can use CondaPkg.jl (https://github.com/cjdoris/CondaPkg.jl) to setup Python dependencies with version control. I haven't played with it too much but it seemed to work out for what I tried. Indeed the reason why I haven't had too many test cases is because in SciML we removed all Python dependencies since they were the main source of instability. PyDSTool.jl, FEniCS.jl, SymEngine.jl (through ParameterizedFunctions.jl and ModelingToolkit.jl) were the biggest development burdens because of the Python deps changing function names all of the time until they were deprecated and replaced by pure Julia packages, so I definitely know the pain.
Most of my time isn't academic or writing code. Most of it is focused on enhancing algorithms to achieve what's required for new methods to work deployed in production environments such as the Pumas clinical pharmacology work, and now working on what's required to get scientific machine learning point-and-click GUI ready. I always leave a little bit of time in mornings and weekends though for some coding, and a little bit a day goes a long way after years.
I stay away from code rewrites like the plague, which is why SciML maintains so many wrapper packages. It's less work and if there's nothing new then rewriting is thankless work. Unless we have some kind of angle for something new in the algorithm, we just recommend someone use the same old wrappers (for instance, IDA with fully-implicit DAEs). We won't beat the C/Fortran code without something new. However in most areas there's lots of interesting research to be done. I could "sabbatical as an academic" and spend the next 3 years just improving explicit Runge-Kutta methods: those for example are probably still 4x away or so from what I think is theoretically possible, but that's not going to happen any time soon since we have some real applications to focus on.
Those package deprecations mentioned above were deprecated by community efforts (BifurcationKit.jl replaced PyDSTool wrappers and was done by Romain Veltz, FEniCS wrappers were largely replaced by Gridap, and SymEngine was replaced by Symbolics which is largely the work of one of the Julia Lab PhD students Shashi). Even those had a largely new element to them though, with BifurcationKit focusing a lot on recent algorithms that other bifurcation software don't have (like the deflated Newton methods), and Shashi's Symbolics.jl work focusing on generality of term rewriting systems to allow for alternative algebras.
Think you've dodged the point entirely by fixating on a word rather then the sentiment. Isn't it in your professional interest to endlessly promote Julia at all costs. To find tools in other languages and make sure they are available in Julia, etc?
That's basically my point. Readers should be aware of who is making suggestions and why they might be making them. You have a clear status and financial drivers to say "only use Julia, it's ready for anything, it's fine" while not saying any of the flaws other then "it's fixed if you compile the branch of the grad student I asked to fix it's PR".
Also the type of work you do is incredibly rare. Most people considering trying to use Julia for their day job don't have the resources you have nor the needs or desires you have. In most cases getting one of the most foremost scientific computing in Julia experts take on what tools they should use really doesn't map well to practical users.
So much for solving the 2 language problem. Everytime I ended up in a similar situation the Julia code was rewritten either by me or someone else in c++ for practical/performance reasons. Hope you consider the same. The libraries for doing mathematics in C++ are surprisingly good and you might be surprised to find how easy parallel processing and fine tuning is in c++. In some ways it's less cognitive load than Julia because it's more explicit...
My problem is not with Julia, my problem is with the Python ecosystem and its dependency management. Not sure how you can read what I wrote and reach that conclusion.
We run Julia code in production. These are compute-heavy services called by other parts of the app.
Version upgrades are normally easy. Upgrade, run the unit tests, build the Docker images and deploy to K8s.
Maybe we've been lucky, but since 1.3 we've never had big issues with version upgrades.
That's wild, I've seen huge performance regressions from changes to Base, among commands being dropped, irreconcilable breakages with basics of the ecosystem, spurious bugs in the networking libraries that are nearly impossible to chase down, and the menagerie of compatibility with essential packages break. I stopped caring around 1.7 when I realized this was the norm and it wasn't going to change. You must be honed in on some specific packages with a lot of custom code.
