I would like to create an external application that will provide users with a questionnaire, save their answers to a database and give recommendations based on their answers. or simply display the recommendations if the user has already previously filled the questionnaire. Therefore this application needs access to the current customer account. It will ask the user to log in before the recommendations are provided, as the questionnaire answers needs to be saved in the database with a customer id.
This page/application will be part of a url for shopify.
is this possible? and what would be the best way? as i'd like to have everything on shopify.