Core Network Services provides network connectivity for PayPal's site infrastructure. To address 5 9s’ site reliability goals, the demand for the network to perform at its best keeps growing. PayPal transformed its data center networks by deploying white-box leaf/spine designs to help with horizontal scaling, low latency, and resilience to failures. By developing a common framework layer, PayPal is able to address network automation/service API needs in a multi-vendor environment. PayPal will discuss the design approach, lessons learned and how it is leveraging various vendor technologies in its transformation journey.