A developer transformed a basic Node.js e-commerce app into a resilient system by implementing HAProxy for load balancing. They configured distribution strategies like round-robin and active health checks to ensure traffic routes to healthy backend instances. SSL termination was handled at the load balancer level, offloading CPU work from backend servers.

To gain deep system insights, they instrumented the Node.js backend using the Prometheus client library, exposing custom metrics for request latency, error rates, and memory usage. Grafana dashboards then visualized this data, overlaying metrics from the backend and load balancer for comprehensive observability and proactive issue detection.

The entire stack was orchestrated with Docker and `docker-compose`, ensuring consistent environments from development to production. This hands-on project moved the author from theoretical knowledge to practical implementation of core DevOps tools, solidifying skills in scaling, resilience, and observability for distributed systems.