End-to-end IoT architecture integrating six ESP32 sensor nodes (temperature, humidity, pressure, motion, light, gas) through a WiFi gateway and MQTT broker for real-time data collection. Data flows from field devices via TLS 1.3-encrypted MQTT transport through Mosquitto/HiveMQ broker with authentication and load balancing to a processing layer running Node-RED or Kafka streams. Backend services built on Node.js/Python handle business logic, trigger alerts, and persist data to InfluxDB time-series, PostgreSQL relational, and Redis cache layers. Grafana and Kibana dashboards, web panels, and mobile apps provide real-time monitoring and historical analysis. This architecture demonstrates secure, scalable IoT data ingestion with multi-layer storage and comprehensive observability for industrial and smart-building deployments.