Architecting systems you can build from scratch or evolve an existing one. A lot of pros and cons on both, but one of the pros of the new ones is how clean can be.
I have been for some time with SlaterLabs, building a core banking solution in .NET. As soon as we started to have the first bits we went to a HP lab in Stuttgart to see if we can compete on the big leagues.
The figures were amazing, more than 7,000 business transactions per second with a average response time under .1 second.