We previously designed and implemented a payment module for MEI Solutions' Electronic Payment System so that they could execute their $300 million deal with Vital Processing Services. Having successfully delivered the module on time and within budget we were a natural choice when it came to upgrading the user interface.
The original user interface was character based and dated. It reflected poorly on the product and left a negative impression in the marketplace. Human nature being what it is, it's difficult to overcome negative first impressions. We replaced the existing interface with a modern graphical user interface that was both visually appealing and fully functional. Implementation was accomplished using the C/C++ programming language and the Qt graphical toolkit.
The new interface was independently tested and found to be functioning correctly within a week, however, an upper level manager extended the period for acceptance testing to well over six weeks. He explained that he had experienced a number of "bad" software projects and was finding it difficult to accept such easy success. In the end we both earned a great deal of respect for each other.