Teams often choose the Premium or App Service Plan for Azure Functions to avoid cold start delays or enable VNET connectivity, especially early in a project when performance concerns dominate. However, these decisions are rarely revisited—even as usage patterns change.
In practice, many workloads running on Premium or App Service Plans have low invocation frequency, minimal execution time, and no strict latency requirements. This leads to consistent spend on compute capacity that is largely idle. Because these plans still “work” and don’t cause reliability issues, the inefficiency is easy to overlook. Over time, this misalignment between hosting tier and actual usage creates significant invisible waste.
Azure Functions are billed differently depending on the hosting plan selected.