In theory, there is no difference between theory and practice; in practice, there is.
In the second part of this book, we concentrated on the principles of event processing, giving examples to show how these principles are used in practice. In this chapter we change our emphasis and focus explicitly on the implementation of event processing applications. The implementation-related topics we discuss are language styles, non-functional properties, performance optimizations, and validation. These are the major engineering topics behind implementation of event processing applications. In summary, this chapter discusses the following topics: