Are you familiar with GraphQL? What is it, how does it look, and why is it needed if REST exists?

GraphQL is a query language for APIs and a runtime for executing those queries, developed by Facebook. Unlike REST, where the server defines the data structure and endpoints, in GraphQL the client constructs the query itself, specifying exactly what data it needs.

A GraphQL query looks like a tree of fields, for example:

{
  user(id: "1") {
    name
    posts {
      title
      comments {
        text
      }
    }
  }
}

This allows obtaining precisely the data needed, without redundancy and additional requests.

Why use GraphQL if REST exists:

• Flexibility: the client requests only the needed fields.
• Fewer requests: related data can be fetched in a single request.
• Self-documenting: the schema describes types and relationships.

REST is simpler and well-suited for simple APIs, but for complex relationships and diverse data, GraphQL is more convenient and efficient.