Did you develop JSON schemas yourself?

Yes, I have developed JSON schemas for data validation in APIs and configuration files. A JSON schema allows describing the structure of a JSON object, data types, required and optional fields, as well as additional constraints, such as minimum or maximum string length.

An example of a simple JSON schema for a user object:

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "name": {"type": "string"},
    "age": {"type": "integer", "minimum": 0},
    "email": {"type": "string", "format": "email"}
  },
  "required": ["name", "email"]
}

Such a schema helps automatically verify the correctness of incoming data and simplifies integration between services.