Writing code is a useful superpower in type design (a discipline potentially rife with repetition and redundancy – after all, type designers typically handle not one object but families of fonts with thousands of glyphs). I often write little scripts that help me work faster, more easily, or more precisely. Some of them have developed into little tools that may be useful for other designers, too. I’ve posted the source code for these on my GitHub account.
Apart from these publicly released tools linked to below, I also write custom code; examples include this stroke-thickness visualization script for Frere-Jones Type or code generating website graphics for Bold Monday.