The best technique I've found for staying sane when working in a large number of languages is to configure your editor to highlight errors based on language. If

The best technique I've found for staying sane when working in a large number of languages is to configure your editor to highlight errors based on language. If you use perens where you're not supposed to, your editor should tell you right away. No need to go find an example. This becomes less useful when it's "which library do I use" or "what is the idiomatic way to do this in X language".