I have a single site that captures form data (faculty profiles) that I want to pull into other sites using short code. My plan is to write plugin for the form input site that allows configuration of variables for form elements (different colleges, programs, dates, etc.) and puts these into a custom table. Then write another plugin that allows me to set filters (specific college) and then processes shortcodes that allow me to display a list of faculty members based on variable values passed via the shortcode OR displays a single faculty member's profile.
All of these sites exist on a single server. Some are WP Multisite installs while others are single installs.
What would be the preferred method (most secure and best performance wise) for pulling the data from the database of the site that captures the form data into the other sites? JSON or PHP?