IoT device management system built with Spring Boot 3.5.7 and reactive programming (Spring WebFlux).

• Framework: Spring Boot 3.5.7 (Java 25)
• Reactive Stack: Spring WebFlux, Project Reactor, R2DBC
• Database: PostgreSQL 17.2 (accessed via R2DBC)
• Resilience: Resilience4j (Circuit Breaker, Retry, Timeout)
• Observability: Prometheus, Grafana, Spring Boot Actuator
• Testing: JUnit 5.12.2, Testcontainers, K6

• For Development: Java 25, Maven 3.9+, Docker & Docker Compose
• For Testing Only: Java 25, Maven 3.9+ (Testcontainers provides PostgreSQL automatically)

# Start application with PostgreSQL
make start

# Start application with observability stack (Prometheus + Grafana)
make start-obs

# Stop application
make stop

# Run all tests (uses Testcontainers, no Docker Compose needed)
make test

• Application: http://localhost:8080
• Swagger UI: http://localhost:8080/swagger-ui.html
• OpenAPI Spec: http://localhost:8080/v3/api-docs
• Health Check: http://localhost:8080/actuator/health
• Prometheus Metrics: http://localhost:8080/actuator/prometheus
• Grafana: http://localhost:3000 (admin/admin)
• Prometheus UI: http://localhost:9090

make start       # Start application with PostgreSQL
make test        # Run all tests (68 tests, uses Testcontainers)
make stop        # Stop all services
make logs        # Show application logs

See Development Guide for all available commands and development workflows.

• Development Guide - Complete development commands and workflows
• Architecture - Package structure and dependency rules
• Resilience - Circuit Breaker, Retry, and Timeout patterns
• Testing Guide - Test strategy and coverage
• K6 Performance Testing - Load testing with K6
• Observability - Monitoring and Grafana dashboards

• ✅ Reactive Programming: Non-blocking architecture
• ✅ Resilience Patterns: Circuit breakers, retries, timeouts
• ✅ Observability: Structured logging, metrics, dashboards
• ✅ API Documentation: Auto-generated Swagger UI
• ✅ Testing: 68 tests (Testcontainers, no Docker Compose needed)
• ✅ Performance Testing: K6 load, stress, and spike tests

Device States:

• AVAILABLE - Device is available for use
• IN_USE - Device is currently being used
• INACTIVE - Device is no longer active in the system

Domain Rules:

• Creation time cannot be updated
• Name and brand cannot be updated if device is IN_USE
• Devices in IN_USE or INACTIVE state cannot be deleted
• INACTIVE devices can be updated (to allow reactivation)

This project is licensed under the MIT License. See LICENSE for details.