Observability is crucial for understanding and managing the behavior of complex software systems, especially as workloads increasingly shift to distributed cloud-based services. OpenTelemetry, an open-source tool, has become a standard solution for making systems observable by instrumenting telemetry data, allowing developers to gain insights into software performance and issues beyond traditional logging capabilities. It supports traces, metrics, and logs to provide a comprehensive view across application boundaries, enabling better error detection and performance monitoring. A demo series explores using OpenTelemetry to add observability to a distributed web application, showcasing how traces can follow request execution flows and metrics can track system performance. The series also emphasizes the importance of connecting to analytics backends like Dynatrace for data analysis and visualization, illustrating the setup process and benefits of integrating OpenTelemetry for enhanced system monitoring.