Architectural partitioning should reflect the geographic partitioning
The architectural partitioning should reflect the geographic partitioning, and vice versa. Architectural responsibilities should be assigned so decisions can be made (geographically) locally.
Communication patterns between project members follow geographic distribution. Coupling between pieces of software must be sustained by analogous coupling between the people working on that software. People avoid, or have more difficulty and expend more effort for the same effect, communicating with people who work in other buildings, other towns, or overseas. Where communications channels would expect to carry much traffic, it is advantageous to have the ends co-located. If geographical distribution is necessary, then it helps if the channels that must be remote are those that would carry comparatively little traffic. So, when people need to cooperate a lot, put them close together. For the remaining cases where remote working is necessary, work FaceToFaceBeforeWorkingRemotely.