There was data redundancy in the various spreadsheets that they used to manage their company, plus concurrency and scalability issues due to binary file formats that you cannot easily diff. So they decided to build their own solution. After all, writing and managing invoices the way they need cannot be that hard – or so they thought.
This is the story of how they went through iterations and rewrites, and what they have learned along the way. Well, they certainly learned to better understand some of the advice they give to their clients.