The most important takeaway from this book is the importance of measuring. You need to measure problems or you can't fix them. You won't even know when you have fixed them. Measurement is the key to fixing performance issues before they become noticeable. Slow operations can be identified early on and then they can be fixed.
However, not all operations need optimizing. It's important to keep a sense of perspective, but you should understand where the choke points are and how they will behave when magnified by scale. We'll cover measuring and profiling in later chapters.
