APIs have become an essential ingredient of Digital Transformation and other initiatives to modernize IT and organizations. However, while APIs are an essential ingredient, they are not everything you need, and thus only focusing on APIs may lead to disappointment when expectations are running too high. In short, APIs are necessary for improving organizational fitness, but they are not sufficient. The hard work of changing an organization also has to happen in other areas than in the technical infrastructure. After looking at some common patterns of "Acute API disillusionment", we will have a look at how a structured approach to transformation initiatives can help to make sure that all necessary parts of the transformation process are tackled simultaneously, or that in case of more serial approach, expectations are adjusted accordingly. APIs are an essential ingredient in modern IT architectures, but understanding their possibilities and limitations is important to get the most out of your API investments.