GuestTracker is the largest project I have developed from the ground up and one that is still actively maintained and extended with new functionalities. It is a system for tracking guest attendance at conferences and similar events. The system automates and streamlines the process of sending invitations as well as guest registration upon arrival. It can also be used for access control by sending personalized documents via email.
The system consists of two main components: a web-based administrative application and a mobile application for on-site use. The entire backend was built using the Spring Boot framework. Automatic invitation delivery via email is enabled through integration with Microsoft O365.
The administrative web application allows for event creation, guest list management, and the sending of email invitations containing personalized QR codes and accompanying documents. It also provides access to event statistics and real-time attendance monitoring.
The mobile application was developed in Java and is intended for on-site use, typically at event entrances. It enables organizers to browse guest lists and perform quick check-ins either by scanning QR codes from invitations or by searching based on guest information. To ensure that check-in data is instantly reflected in the admin interface, the application uses WebSocket protocol for real-time communication, providing a complete overview of the event's flow and ensuring effective access control.
The application is used by dozens of companies across Serbia and records approximately 100,000 guest check-ins annually.























