latency - how do you build a platform with high performance if every customer request has a network of n services to traverse for every operation?
You'll want to issue requests concurrently, use timeouts liberally, and implement fallbacks to cached/calculated data in the event that one of the services fails or misbehaves. Those are just a few guiding principles that will help when building a SOA (service-oriented architecture). Netflix has a great blog post on the structure of their platform [1]. They even open-sourced Hystrix [2], the library they use internally.
[1] http://techblog.netflix.com/2012/02/fault-tolerance-in-high-...