Advertisement Management Platform for Digital Hoardings

Digital hoardings (large outdoor LED screens) were being managed manually -- someone would physically go to each device with a USB drive to update ads. The client needed a way to push content to dozens of Android-based hoarding devices remotely, in real time, from a single dashboard.

The Challenge

The hoarding devices sit on unreliable cellular networks. Content updates need to reach them instantly when an admin schedules a new ad, but the system also has to handle devices going offline and syncing when they reconnect. Security was critical too -- we couldn't allow unauthorized content to appear on public-facing screens.

How I Built It

I chose AWS MQTT as the real-time communication layer because it's lightweight enough for constrained devices and handles intermittent connectivity gracefully. When an admin updates content through the React admin panel, the backend publishes an MQTT event. Each hoarding device subscribes to its own topic, receives the signal, and pulls the latest media via REST API. Media assets are stored on S3 with signed URLs for secure access. I also implemented device registration, de-registration, and per-device content management so operators could control each screen independently.

What I Learned

This was my first deep dive into IoT-style architecture -- bridging web systems with physical hardware over unreliable networks. I gained practical experience with MQTT pub/sub patterns, device lifecycle management, and building admin tools that non-technical operators could use confidently.