Robert Martin

The authors cover the design process where customer "stories" are partitioned off into deliverables (small ones are called "iterations," which are combined into larger "releases"). The authors give you sample project estimation for how long it will take for each step. They provide the details of the code that does the work for each step, along with sample automated tests. (In XP, code is not "accepted" by clients until it can be verified with tests.) The authors also show off how their initial estimates sometimes went wrong. (Most readers will be struck that almost in all cases, initial estimates for programming time are overestimated by the authors.) However, they do share a significant snag in the process of a typical miscommunication with their client about promised functionality, which is sure to resonate with many readers. By the end of the book, they share their final thoughts on what works and what doesn't in XP, along with some advice for "scaling" XP onto larger projects and teams.