What challenges do you face to build API on a data source?

There is not even a single application that exists without an API. APIs simplify the overall architecture of the application and allow microservice architecture. As we build APIs, what challenges would you face and what do you think should be simplified? In my view, here are the challenges: - Getting access to the data source - Get only required privileges on the data source - Implement business rules in the API that limit the data access based on the user login - Apply dynamic masking to hide certain data that is confidential Looking forward to hearing the feedback from the product unit family! Best Regards JG https://www.ekahaa.com