Connectivity between data centers in a hybrid cloud system is optimized by pre-loading a wide area network (WAN) optimization appliance in a first data center with data to initialize at least one WAN optimization of application. The first data center is managed by a first organization and a second data center managed by a second organization, the first organization being a tenant in the second data center. The described technique includes receiving application packets having the application data generated by an application executing in the first data center at the WAN optimization appliance from a first gateway in the first data center, and performing the at least one WAN optimization on the application packets using the pre-loaded data to initialize the at least one WAN optimization.