JSON is the standard when it comes to interfacing between different systems, being smaller and more dynamic than its predecessor XML. JSON is easy to understand, code and adopt in your legacy system. IBM has made this easier still with their JSON integration into DB2 with functions like JSON_Table and JSON_Array, the image demonstrates this usage in RPG.
JSON is a key API enabler. its no-frills approach focuses on data and relationships. JSON adoption internally can springboard future enhancements as your application evolves.
DB2 JSON creation by default uses a CCSID of 1208 (UTF-8) thus eliminating the need to apply translation and conversion process.