A bridging system is a home-grown routing solution to route traffic to either a new or legacy system during data migration. The bridging system is used to support core systems transformation efforts, mergers and acquisitions such as Billing System Transformation, and Order Management System Transformation or Consolidation in various industries including telecommunication, transportation, and consumer/commercial products distribution. The bridging system architecture mandates scalability, flexibility, and high performance to minimize the impacts of system downtime and to make the system transformation seamless to end users during data migration. The bridging system can also be architected to serve as a data segmentation router to support an Active/Active data center model after the data migration is complete. This presentation will show what a home-grown bridging system architecture looks like; how it works end to end to satisfy business needs in terms of system architecture, the technology stack, major components design, and integration to impacted applications; and performance considerations.