Distributed design allows for basic service failover.
The 737 is a great design for branch offices or running as a starter managed private cloud. All dedicated services run redundantly on Node 7 back end machines (providing critical failover functionality) while being analyzed, secured, and load balanced by a Node 3 front end. Capable of handling over half a million simultaneous connections (depending on workload) and providing your critical branch office needs even if your Internet connection is down. Because the Node 3 remains a single point of failure, regular maintenance windows are required to support this design.
When your business grows to the point that uptime is critical, the 737 is a simple upgrade away from becoming a 767 design. Upgrading offers complete failover support even when one of your Internet Service Providers goes offline.