When enabled, node caching helps speed up execution of your builds by avoiding having to repeat time-consuming processes, such as installing or loading large amounts of dependency data. This feature is available only on dynamic node pools.
When node caching is enabled for a dynamic node pool, Pipelines pauses your node after executing a step, instead of terminating it after the specified idle time. When the next step executes, the paused node is restarted, retaining any Docker images or dependencies that were installed as part of the previous step. This greatly speeds up builds that pull or build Docker images as part of their workflow.
In addition, the node is available to execute the job much sooner, since restarting the node from a paused state is much faster than provisioning a new node. So if your build takes just a few minutes to execute, you save on the node provisioning time for every build, which adds up quickly.