Why performance is important

Maybe you just started reading this book out of curiosity and you're asking yourself this question: Why is performance important? Isn't that a thing of the past, when we didn't have enough CPU power and memory, and when our networks were grinding to a halt? In today's high-tech world, we have enough resources—the computers are so insanely fast!

Well, in principle, you're right to some degree, but consider the following:

• A faster program runs more quickly, consuming less power along the way. This is good for the planet (if you're running it in a big server farm) and good for your user (if you're running it on a desktop computer).
• A faster program means that it can serve more requests in the same time than a slower one. This is good for business, as you'll need to buy or lease fewer machines to serve your customers, and, again, it's good for the planet!
• Faster software in today's business world's cut-throat competition means an advantage in respect to your competitors. This is nowhere more evident than in the world of automated trading (which is, by the way, dominated by C++), but also the fact that sluggishly-loading websites and programs needing an eternity to start won't be used that much!
• And, lastly, especially on mobile devices, we still have to cope with constrained resources—network speed is finite (light speed) and battery life is finite too—and as faster programs use less resources, they're good for users!

Our quest for performance will hence pursue a three-pronged objective: to save the planet, to strengthen your business, and to make the life of users better—not a small feat I'd say!