This book is for readers with backgrounds in science engineering who have experience in computer programming but who lack training in software engineering. It teaches object-oriented design patterns in a real-world context, which is relevant to computational science. Coverage is centered around a case study in software development in e-science using the Java™ programming language. A graphical front-end for browsing and visualizing scientific waveform data is progressively refactored using important design patterns for object-oriented software and the final product is ready for porting onto the Grid.