Rajiv Perera, a software engineer, has developed Caretime, an application that helps healthcare employers track caregivers' locations, work schedules, and activities. Rajiv uses Twilio for SMS and voice functionality, the MapBox API, Google Address API, and a private geolocation service to capture and verify caregiver data. He chose NodeJS as his backend technology due to its scalability, particularly when handling high volumes of interactions from healthcare agency clients. Caretime's simplicity on the surface belies its complex backend capabilities, which include biometric voice identification, geolocation, HIPAA compliant recording, text records, and voice records.