The winner of the Alerts & Notifications Twilio Developer Contest is Carl Tyler for his Airplane Booking System, which uses Twilio's API to provide a paper-based system with additional capabilities such as SMS notifications and IVR integration. The system was built using Lotus Domino and Dhtmlx.com's Scheduling UI in just two weekends, making it accessible to non-technical users. The flying club members have found the application easy to use, and Carl plans to productize the solution for other flying clubs. The contest aims to encourage developers to build Twilio apps, with this week's challenge focusing on Powering Up Customer Service.