System architects need to cast their nets wide to incorporate the best thinking. Another fine text (especially considering the price) is “Microsoft Application Architecture Guide, 2nd Edition,” published in 2009. It is, of course, written in service to the technologies of Microsoft, but the general discussions are quite good and it has many helpful links to additional resources.

Other than Fowler, the most valuable texts on architecture are, in my opinion, the three volumes in the “Pattern-Oriented Software Architecture” series (starting with Buschmann et al., a.k.a. “The Siemens Book”). These texts are a little long in the tooth now, but their age actually throws some of the benefits and drawbacks of the patterns into starker relief. For instance, I’m not sure that I’ll see a 21st-century enterprise using the Unix-style “Pipes and Filters” architecture, but I’m quite positive that, in some discussion, a knowledge of “Pipes and Filters” will help clarify an issue. And, hopefully, keep some system from being a Big Ball of Mud.

Larry O’Brien is a developer evangelist/advocate for Xamarin. Read his blog at