Protobuf - Protocol buffers are a language-neutral, platform-neutral extensible mechanism for serializing structured data.
GraphQL - GraphQL is a data query language and runtime to request and deliver data to mobile and web apps.
Apache Thrift - An interface definition language and communication protocol for creating cross-language services.
JsonAPI - Application and Data, Languages & Frameworks, and Query Languages
Messagepack - An efficient binary serialization format.
Django REST framework - Django REST framework is a toolkit for building web APIs.