If you agree with this principle, I think the end result is that you choose the most popular language for some window. For banks and airlines, you conservative

If you agree with this principle, I think the end result is that you choose the most popular language for some window. For banks and airlines, you conservatively pick a large window. At one point that ended up being COBOL. That is slowly migrating to Java now. I suspect it will move to TypeScript in about a decade or so. For new code today, I'd probably pick TypeScript. A few years ago, I'd have picked Ruby. Before that, Python, Before that, Perl/CGI. Before that, Java. Before that, C++. I wonder if at some point the tides will turn back to writing pure-personal-computer-and-no-cloud C/C++ Windows applications.