CoolTrack IoT Platform

What it is

CoolTrack is an IoT monitoring platform for commercial refrigeration in retail stores and supermarkets. It tracks cabinet temperatures in real time, raises alarms when readings go out of range, generates HACCP compliance reports, and gives store operators a dashboard to manage their equipment.

The system runs on two Spring Boot microservices — a dashboard backend that powers the web UI, and an MQTT consumer that ingests telemetry from refrigeration cabinets.

What I built

I handled the entire backend for this project. That included both the dashboard API service and the MQTT consumer service, from initial setup through production deployment.

On the dashboard backend, I built the APIs for store and cabinet management, telemetry queries against InfluxDB, alarm and notification flows, HACCP report generation, service request handling with file attachments, and command dispatch to cabinets through a separate MQTT publisher. The service integrates PostgreSQL for relational data, InfluxDB for time-series metrics, AWS SES for email notifications, and AWS S3 for file storage.

On the MQTT consumer, I built the subscription and routing layer that receives cabinet telemetry from the broker, parses incoming payloads, categorizes metrics, writes them to InfluxDB, and forwards alarm-type readings to the dashboard backend. This service also handles reconnection logic, retry behavior, health checks, and service-to-service authentication.

I also worked on frontend integration when needed — connecting the dashboard UI to backend APIs and making sure the data flows rendered correctly on the client side.

Tech stack

• Spring Boot — both microservices
• PostgreSQL — relational data (stores, cabinets, users, service requests)
• InfluxDB — time-series telemetry storage and queries
• MQTT — device-to-cloud telemetry ingestion
• AWS SES — transactional email and notifications
• AWS S3 — file attachment storage
• Docker — containerized deployment