The complexity of the generated json of the data model, especially for rich text content. Very confusing and optimized for Contentful internal reasons. They are lacking some basic features that are making the content model much harder to manage. A few examples:
1. You can’t embed object models directly in content without making them a shared object first. This is like trying to write a document and embed tables and info boxes, but be forced to create these as separate documents and link them to your document. This grows to a huge problem the larger your content grows.
2. The content management APIs and the content delivery APIs (the creation and editing vs serving content to end users) is slightly different, but just enough to make your code inconsistent and confusing between the two use-cases.
3. Lack of easy ability to apply permissions based data access for end users
4. Different SDKs (namely JS, Java and REST) are not unified enough in concepts.
5. Support is very slow. I had simple “how/why” questions answered months after I asked them.
6. Learning curve of the ask and rendering of content is quite steep.
7. Scheme migration between versions is problematics and required 3rd party tools to track your changes between a dev and production versions of your content object model. Review collected by and hosted on G2.com.