After some months of nothing but backend development I started to work on my customers Angular frontend application again. I noticed that starting a single karma test took way longer than it used to be. A simple test for a pure function in headless chrome took about half a minute, in which the actual test only took some milliseconds. That was really annoying, because in my current refactoring task I have to execute lots of tests very often. Searching, browsing the karma issues and so on didn’t help, so I want to describe, how I found out what has been causing the problems.