Keep an inbound API up while we rewrite a single process

Digital channels already call this CICS transaction. We are replacing only one process behind it. How do callers keep working?

Leave an inbound system API in front of the transaction you are not ready to retire. [[product:ol-integration|OL Integration]] is where that contract, the host connector, and the deployed service live. Channels keep calling the same contract. You change what the method does when the new process is ready, instead of asking every caller to move on day one.