Squarescale has been designed from the start to allow you to scale. There are a few things in your project that you can increase to perform better.
The first step in scaling is probably to scale your services. With each service, you can choose the number of instances of that service to run. Squarescale is going to automatically find some room for them in your cluster.
Then, when you reach the limits of your cluster, you can always scale it up. Just increase the cluster size and you'll have new machines to put things on.
And of course, as you scaled things up, it's also possible to scale your cluster and your services down the same way you scaled up.