It can be hard, but it depends on the level of the developer’s experience. Developing cloud applications can be difficult for those who are new to the cloud or who have limited experience with cloud-based development.
However, for those who are already familiar with the cloud and have experience with developing cloud-based applications, it's likely that the switch to developing apps for the cloud will be a relatively easy process.
The main challenge associated with developing cloud applications is that developers need to understand well both the platform they’re developing on, and the app’s architecture.
They also need to be able to design an application in a way that takes advantage of the scalability and elasticity of the cloud. Fortunately, there are many online resources available that help with this process.