Project use Java because of the security requirements for application that handles real financial data as well as for it's performance and ability to conduct scheduled operations easily. As for framework Log Bank is build on Spring framework which provides easy and fast way to create RESTfull api.
Hypermedia driven API was also required to build client application in Java Script using Angular Js framework.
Our role in this project was maintaining it. We also developed small features after first release that growing community required.