Any growing application will encounter some kind of performance problem
Performance and scaling have nothing to do with the programming language or framework used. Any growing application will encounter some kind of performance problem in it's lifetime.
Finding out why your application is not performing as you expected can be very difficult. And because the rails framework offers a wide range of caching and performance options, it is even more difficult to actually solve a performance issue correctly.
This is where railsdoctors comes in. Because of our experience we can help you find the root cause of your problem and how best to fix it.
In the process we have developed several tools, like the widely used request log analyzer gem.