Doing terrible things to your (data analysis) code to make it better

Test the heck out of your code!

One thing that surprised me was that the code itself was rarely the problem. He occasionally had some comments about the way I wrote or structured the code, but what I clearly had no idea about is testing my code.

I dreaded handing my work over to him for inspection. I slowly, painfully learned that the truly difficult part of coding is dealing with the thousands of ways things can go wrong with your application at any given time – most of them user related.