The Scala compiler is slow. However with some care over code organisation you can limit what needs to be recompiled in most cases. Read and heed this blog post:

The Scala compiler is slow. However with some care over code organisation you can limit what needs to be recompiled in most cases. Read and heed this blog post: http://www.chrisstucchio.com/blog/2014/bondage_and_discipline.html http://www.chrisstucchio.com/blog/2014/bondage_and_disciplin...