Justin Edelson doesn’t blog a lot, so when he does you should pay attention. He is one of the minds in charge of ACS AEM Commons/Tools/Samples. And you know how much we love the ACS AEM Suite. With the expected release of AEM 6.3 later this spring, you should be aware that you will likely need to recompile your code if you are going to upgrade your site from anything pre-6.2. You should read Justin’s post from April 2016 where he details what you should look out for to determine if you need to recompile your code.