User System
For speed-kini.de I extended the standard user system with a custom registration form. GravityForms offers a simple add-on which can provide custom registration and profile update pages (http://www.gravityforms.com/add-ons/user-registration/). The custom field values can be easily accessed in PHP later.
REST API extension
In order to provide dynamic front-end functionality, I extended the built-in REST adapter for my specific purposes. I started with JSON data about riders which is displayed in their user profiles. There is a difference between registered users who a WordPress user profile and people who are only identified by their names. There are different REST paths for both possibilities.
Frontend Ajax and Google Charts
Javascript loads the user JSON data via an AJAX request utilizing the REST interface. The incredible Google Charts API cares about displaying the data in nice line and pie charts.
