How I Built a Serverless IoT Pipeline on AWS

Water quality testing normally takes between 24 and 48 hours. This makes it almost impossible to monitor water quality in real-time, especially in cases where the water has to be clean in real-time.I wanted this time taken down to seconds. That is why I created a real-time water quality monitoring system using ESP32 sensors, AWS IoT Core, Lambda, and DynamoDB — a production-ready pipeline, not a demo. The Problem Most IoT tutorials go this far: Sending a temperature reading Displaying it on a dashboard They don’t cover what happens when you need to: Handle 100K+ messages per hour reliably Run ML inference on every incoming reading Trigger alerts within <5 seconds Keep costs under $2 per device/month The Architecture This system is built as a totally serverless, event-driven architecture where each component is triggered by incoming data rather than continuous operation. It eliminates the need for infrastructure management as there are no EC2 instances, container orchestration layers