Yes! I've always hated the common kata, because for every dev writing software for a bowling alley, there are 200,000 devs writing software the sends invoices o

Yes! I've always hated the common kata, because for every dev writing software for a bowling alley, there are 200,000 devs writing software the sends invoices or stores documents. When I'm teaching TDD, the kata I have everyone go through is a simple order system. The requirements are something like: A user can order a case of soda The user should have their credit card charged The user should get an email when the card is charged The user should get an email when their order ships If the credit card is denied, they should see an error message (etc....) This way they can think about abstracting out dependencies, an IEmailService, a ICreditCardService, etc. There are no dependencies for a Roman Numeral converter.