You code the app. You've used Test-Driven-Development for it, because you do things the right way. You care about the quality of your code. You ship it. The job is mostly done! EXCEPT, of course, now that your app has -you know, users- performance is down. You've got a Redis instance caching sessions and database queries, but it's not enough! Your problem needs a bolted-on solution - maybe throw something else at it, like Varnish? We don't do Performance-Driven-Development in PHP, and we should. The problem is in the code, not the caching. In this session I'm going to show you how it's done.