Drag nodes Parallel Chunk Start and Parallel Chunk End from the node repository to this part of the workflow. Connect the output port of the CSV Reader node to the input port of the Parallel Chunk Start node.
When configuring the Parallel Chunk Start node, select 'Use automatic chunk count'. When configuring the Parallel Chunk End node, select 'Add Chunk Index to Row ID'.
Connect the output port of the Parallel Chunk Start node to the input port of the Call Workflow Service node. Connect the output port of the Call Workflow Service node to the input port of the Parallel Chunk End node.
Click on the top right of the Parallel Chunk End node and drag the line that appears until it connects to the input port of the Timer info node. Execute the workflow now and see how much time it takes to run it (in ms). It should be significantly faster than the previous execution from Step 1.