Interfaces written in JSON

The context

Mercado Libre’s internal platforms use a library that builds user interfaces from JSON files: instead of coding each screen, you describe which components it has and the library renders them. During my first year at OpsIT, while I was learning the company’s in-house technologies and design systems, I worked on that library.

What I contributed

• New components with a high degree of customization.
• A pseudo-language inside the JSON to control how data is displayed without writing separate code:
  • uppercase and other text transformations,
  • date and currency formats,
  • text sanitization,
  • conditional rendering based on the context data the library handles.

Why it matters

Every improvement to a library like this reaches every screen built with it, and makes the next interface faster to build. There were about 15 major improvements in total.