We went live with the API bridge on a Tuesday. By Friday, the warehouse team stopped asking for the nightly batch report because the inventory levels in our cloud dashboard were already current. That was the moment I knew the integration was worth it. The first month was not about big announcements; it was about the quiet removal of a daily bottleneck that had been there for years. The mainframe side still runs its old routines, but now our logistics system talks to it through a secure layer that we can actually monitor. I did not expect the setup to be this calm. There were no late-night calls, no rollbacks, just a clear handover document and a schedule for the next phase.