Continuous delivery and deployment

While Scrum and Kanban enable teams to work on many small pieces independently, most architecture still harkened back to that “software build” tradition that came from physical disks. Yet by the 2010s, the dominant platform for new applications was the web. With the web, teams could update changes continuously. A bug that was found and fixed within hours would have a much smaller impact than a bug found, fixed, and redeployed two weeks later under Scrum. This allowed teams to take risks – if they could only develop an architecture to limit those risks.

One such architecture worth noting is that used by Etsy. The company used PHP, the “PHP Hypertext Preprocessor.” PHP allowed programmers to embed computer code to change web pages as they were sent out. It is also interpreted, with each page a separate file. As long as the programmers didn’t need to update a database or change a shared code library, it was...