With the proliferation of IoT devices, real-time monitoring of their online and offline status is crucial, and one effective method is using PubNub's presence features through JavaScript and Java. This process involves signing up for a PubNub account to access unique keys and enabling the Presence feature in the PubNub Developer Portal. Using JavaScript, developers can utilize the Presence feature to track device status via UUIDs and actions like join, leave, or timeout, displaying this information in the console or storing it elsewhere. Similarly, Java users can employ the hereNow function to monitor device presence, modifying callback functions to manage and store data in an array. These techniques enable up-to-the-second monitoring, essential for scenarios requiring reliable reporting from IoT devices, and have become a standard for any connected IoT system, ensuring users can track device activity in real time.