The IT industry is constantly evolving with the introduction of new technologies. While it is important to keep up with advancements, maintaining legacy systems is equally necessary to ensure that the infrastructure of your organization functions to the best of its ability. Sound knowledge of techniques that can be used for maintaining legacy systems can help you avoid common pitfalls. The book begins with a quick overview of what a real legacy system looks like, how it works, and common issues that may be faced when trying to maintaining it. You'll then explore the architecture of a legacy system in detail and understand each of its components. As you progress, you'll discover a variety of techniques for analyzing a legacy system and how to apply them. Once you get to grips with the security constraints associated with legacy systems, you'll explore ways to secure them. Finally, you'll be able to easily make changes in legacy systems to enhance their performance. By the end of this book, you’ll have developed the skills and confidence to work with legacy systems and efficiently maintain them.