[BeetleB]

> "backends" (not "web backends", but the more general "where the mechanisms are") should know nothing about "frontends" (again, not web, but the more general "user interface of some kind"). This is really just MVC in its most basic sense. One good way I've found to think about this is to assume that there's always at least two UIs running simultaneously. Make sure this can work.

This is one I constantly struggle convincing my colleagues about. It becomes much more "obvious" if you are trying to write unit tests in C++ code[1], but unit tests are a mere side benefit. It's more about reducing coupling.

Currently working on a code base that outputs to an Excel file. We recently started dealing with more data than the Excel file can handle easily, and the system came to a crawl. So we had to allow for the option to output to CSV (easily 100x faster in our use cases). At least now some of my colleagues have a bit of appreciation on what I've been harping on.

The Excel library is still intrinsically tied to much of our code. We've been getting over 15GB RAM usage for data that I'm sure would not take more than 2GB if we manage to bypass the Excel library.

[1] Why does my class that computes X need to know that something called email exists? So to write a test for this class I need to instantiate a whole other set of classes just for output? Just have it "ReportMessage" on the Reporter interface and let whatever class that inherits from it figure decide if the message will go out via email or SMS.