Worst architecture I've seen?

The worst (working here) follow the academic pattern of trying to be perfect when the only measure of 'perfect' should be the user saying "Thank you" or one that no one knows about (the 'it just works' architectural pattern).

A senior developer with a masters degree in software engineering developed a class/object architecture for representing an Invoice in our system. Took almost 3 months to come up with ..

- Contained over 50 interfaces (IInvoice, IOrder, IProduct, etc. mostly just data bags)
- Abstract classes that implemented the interfaces
- Concrete classes that injected behavior via the abstract classes (constructors, Copy methods, converter functions, etc)
- Various data access (SQL server/WCF services) factories

During code reviews I kept saying this design was too complex and too brittle for the changes everyone knew were coming. The web team that would ultimately be using the framework had, at best, vague requirements. Because he had a masters degree, he knew best.

He was proud of nearly perfect academic design (almost 100% test code coverage, very nice class diagrams, lines and boxes, auto-generated documentation, etc), until the DBAs changed table relationships (1:1 turned into 1:M and M:M), field names, etc, and users changed business requirements (ex. concept of an invoice fee changed the total amount due calculation, which broke nearly everything).

That change caused a ripple affect that resulted in a major delay in the web site feature release.

By the time the developer fixed all the issues, the web team wrote their framework and hit the database directly (Dapper+simple DTOs) and his library was never used.