“One that's tricky is slight spelling errors in variable names. So I choose variable names that are very dissimilar, deliberately, so that error won't occur. If you've got a long variable like personName and you've got personNames with an “s” on the end, that's a list of person names, that will be something that my eye will tend to read what I thought it should have been. And so I'd have personName and then listOfPeople. And I do that deliberately because I know that my eye will see what I thought I'd written.”