Once the core requirements are set forth, architects can start working on the building blocks for the solution. The building blocks are like high-level patterns; they specify what major components the system might have. For example, for a middle-tier monitoring solution, building blocks might consist of a message-logging system, a reporting system, a notification system, a dashboard, a data maintenance system, and others. The next step should be to look into a lower level of the architecture; each building block requires patterns to be used. Message logging can be done with the usage of the filesystem, a database, SNMP sending log data into another system, or something else. Before the patterns are selected, evaluated, and thoroughly considered, jumping into a product selection would be a grave mistake. It could cause selecting a tool that might not be fit for the task, a tool that is an overkill, or a tool that requires an enormous amount of configuration effort. Sometimes, building a proof of concept might be required to evaluate the patterns implemented by a technology candidate.

There are many books that have been written on generic patterns, especially patterns of the enterprise application architecture. The most respected series is the series with the Martin Fowler signature. We would recommend Patterns of Enterprise Application Architecture, Addison-Wesley Professional, Martin Fowler, and Enterprise Integration Patterns, Addison-Wesley Professional, Gregor Hohpe, Bobby Woolf, as the most relevant to discussions in our book.