Some time ago, I published the famed Pet Catalog application on Github. It doesn’t seem like much, but there are some hours of work (if not days) behind the scenes. I wanted to write down the objectives of this pet project (noticed the joke here?) and the walls I hit trying to achieve them to prevent others to hit them. Objectives were very simple at first: get the Pet Catalog to work under TomEE, the Web Profile compliant application server based on Tomcat.