> I have seen quite a few programs either fail or nearly fail because of the choice to use something like Python

I'm not surprised, it is very difficult to scale Python to larger teams and projects. I mean people have done it to some degree, but at what cost?

It's much better to stick with a static language like Java or C#. You mentioned pattern matching and discriminated unions at the end of your post, which Java has recently gained, and C# to an extent as well.