Application development is an incremental and continuous process: once an application has been designed, implemented, and deployed, it needs to be constantly monitored and improved. The same applies to real-time pipelines, with additional variables: scalability and capacity. There may be an increase in the volume and velocity of the incoming data or lower latency requirements. Over time, as requirements change, initial design choices need to be reevaluated. Developers and infrastructure engineers clamor to squeeze the last bit of performance out of both the software stack and the hardware. Regardless of the cause and effect, all such projects require rigorous and generous instrumentation—from logging and monitoring to alerting and metrics.