Onward!

Performance optimization is a never-ending battle. New code will slow down the old code. And even the old code you can make faster and faster if you spend enough time on it.

I’ve found that the same applies to this book. I could always add more techniques and best practices. There’s always one more optimization tool that I didn’t cover. That’s why I created a wiki page^[43] with additional resources other readers and I found useful for optimization. You’re welcome to use and contribute to it.

Now it’s time for you to optimize your code.

First, find and fix all performance blunders. We talked about many of them in the first three chapters, so now you’ll spot them just by looking at the code.

Then, see what your logging and monitoring tools report as slow. Isolate the underperforming parts, and profile them. Understand what makes them slow, optimize, measure. Rinse and repeat as necessary. Write a test that will ensure your optimization will not vanish as you change the code.

Finally, step back and rethink how your code runs. You’ll be surprised how fine-tuning your application’s environment makes things faster.

And remember, always measure the effect of any change you make. Not only will you know whether the optimization worked, but you’ll have something to be proud of.

Wouldn’t it be so cool to report 74 times speedup in the commit log? Go ahead and optimize. I’m sure you’ll do that, and even better!