Once upon a time, in the Fabulous Land of Web Shops Where Rivers Were Made of Honey, there was me, fresh and young PHP developer with little experience, and my team leader who was in the industry for 10 years.

It was late in the evening, and I was still at the office. We had to finish a backend for an important client. Quickly, as always. I was exhausted.

My team leader was full of passion, agitating a weird diagram full of boxes and arrows: “Here’s my idea. We should first create two interfaces, put two decorators here and maybe three factories there; we need the system to be flexible as much as we can, the client expect to keep his backend for 20 years. How, and what about abstracting this? It might not be DRY enough though.”