I don't like books prefaces that take me days to read before arriving to the real content, so I will be very brief here. • How many times in the last month have you seen a broken screen in the browser? • How many times did you have to debug in the browser, by looking at the output, inserting debug statements and breaking redirects? • How many times did you perform manual testing, by loading a staging version of your application and tried out different workflows in the browser? If the answer to these questions is more than very few, it's likely that you should give automated testing a chance. Testing can be handled professionally, by writing a test suite that you can run at the push of a button and from the command line. If well-written, this suite will show you a list of localized errors and where to go to fix them. It will eliminate most of the debugging from your day.