Gary Mak has been a technical architect and application developer on the enterprise Java platform for six years. In his career, Gary has developed a number of Java–based software projects, most of which are core application frameworks and software tools. He enjoys designing and implementing the complex parts of software projects. Gary is a Sun certified Java programmer and has a master’s degree in computer science. His research interests include object–oriented technology, aspect–oriented technology, design patterns, and software reuse. Gary specializes in building enterprise applications on frameworks including Spring, Hibernate, JPA, Struts, JSF, and Tapestry. He has been using the Spring framework in his projects for four years, since Spring version 1.0. Gary is also an instructor of courses on enterprise Java, Spring, Hibernate, Web Services, and agile development. He has written a series of Spring and Hibernate tutorials as course materials, parts of which are open to the public, and they’re gaining popularity in the Java community. In his spare time, he enjoys playing tennis and watching tennis competitions.