This book is intended for those who already know some of the concepts concerning compilers and want to quickly become familiar with LLVM’s infrastructure and the rich set of libraries that it provides. Compiler programmers, who are familiar with concepts of compilers and want to indulge in understanding, exploring, and using the LLVM infrastructure in a meaningful way in their work, will find this book useful. This book is also for programmers who are not directly involved in compiler projects but are often involved in development phases where they write thousands of lines of code. With knowledge of how compilers work, they will be able to code in an optimal way and improve performance with clean code.