Scalability depends on the deployment model. If you are implementing it on IBM Cloud or any other cloud, the scalability is easy. In the case where you are using your own data centers or on-prem systems, then you will need to scale the data applications yourself, using local answers. That is also a type of grind on the developer or DevOps team. Small- to medium-sized companies deploy Fuse in their environments because it is cheap. For example, a giant corporation in America that has a lot of money will not use Fuse services, they will use MuleSoft for their integration. In Asia and the Middle East, Red Hat Fuse and IBM are the market leaders. IBM acquired Red Hat, so they have two ESB solutions: an expensive one and a cheap one.