The "SAP Certified Development Associate - SAP Cloud Platform: Enterprise Extensions" certification exam validates that the candidate possesses the fundamental and core knowledge required of the SAP Cloud Platform profile and its enterprise extension scopes. This certification proves that the candidate has an overall understanding and in‐depth technical skills to participate as a member of a project team in a mentoring role. This certificate builds on the basic knowledge gained through a related SAP Cloud Platform training.
It is advisable to read the following eBook from SAP Learning Hub.
Following 3 free openSAP courses are also helpful if you need more depth knowledge or Cloud Application Programming Model and ABAP Restful Programming Model.
Building Applications with SAP Cloud Application Programming Model
Building Apps with the ABAP RESTful Application Programming Model
SAP Cloud Platform Essentials (Update Q2/2019)