One exciting aspect of software programming is that there are usually many ways to accomplish the same goal. Unfortunately, this also presents software engineers with unique challenges when trying to make the best design or implementation choice for each situation. Experience plays a major role, and the learning process is often progressive as one learns to avoid past mistakes. Sadly, though, experience is often a variable concept. I have met several software engineers who, after spending a very long time working on an area, still lacked a basic understanding of how it really worked beyond the repetitive day-to-day tasks they grew accustomed to. I have also met others who have perfected their craft in a field after only a few years of working experience.

This book introduces a few techniques for methodically approaching software development problems primarily using the two “Swiss Army knives” of expert Microsoft Windows developers—namely, the Windows debuggers (WinDbg) and the Windows Performance Toolkit (Xperf). By focusing on why features and components work the way they do in the system rather than simply on how they work or what they do, this book tries to accelerate the process of learning by experience and to minimize the number of mistakes made when approaching new problems. An important part of the process is learning to compare and contrast with known solutions to existing ones.

Software engineering is still inherently a practical science. (Some might even argue it’s an art rather than a science.) While there is certainly no substitute for real experience, the topic can definitely be approached with the same methodical persistence that works so well for other scientific disciplines. In fact, this approach works even better in software engineering because all behaviors can be explained rationally. After all, it is all just code—whether it’s your own code or code written by others that you end up consuming in your software—and code can always be traced and understood.

Although this book deals with several architectural pillars of the Windows operating system as part of its debugging and tracing experiments, my main goal in writing it is less about covering those details and more about encouraging and developing this critical mindset. I hope to demonstrate how this approach can be used for solving a few interesting problems as part of this book, and that you continue to systematically apply debugging and tracing as you expand your learning beyond the topics directly covered here.