Storyblok

Storyblok is also a web service, so you only need to register an account to create a project. It is more difficult to use than Contentful, but has more room for customization. In addition to the main entities, here it's possible to make auxiliary ones to use as components of the main entities. Storyblok allows grouping entities and content independently.

Also, this CMS has a unique feature. It can include your code on the frontend to see a preview of the content being created, which is important for content managers.

Of course, Storyblok has some flaws. It's not beginner-friendly, so a bit of learning is required to understand its interface. Then, it is only available in the paid version. Storyblok also has restrictions for entities, content, and files, but they are much wider than in Contentful.

Finally, Storyblok is a good CMS if you have fairly complex data structures in your project and want to fine-tune them.

Takeshape

TakeShape is a Content Management-as-a-Service cloud platform with an integrated Static Content Generator that prioritizes GraphQL APIs and eliminates the expense and difficulty of creating and maintaining a cloud-scale content experience.

Basically, TakeShape is not your typical headless CMS. It is an API mesh solution that enables you to set up a hosted GraphQL API that unites all of your services and data into a single endpoint along with your content.