BillingZone is a subsidiary of Pittsburgh National Bank (PNC), and provides bill presentment services to major corporate clients. For example, say Acme Fertilizer receives every month a massive bill, delivered on paper and CD, from AT&T. BillingZone would save costs for both parties by importing the billing data from AT&T, storing it, and letting Acme Fertilizer browse the bill, schedule payments, request contest line-items, etc.
The BillingZone system was developed very quickly in early 2000 by Perot Systems to get to market early. Once the service was running, BillingZone wished to understand the system that was built in haste, and to prepare an architectural roadmap to enhance it.
I served as the Technical Lead of a team of about five people on this Roadmap project from July - December 2000.