When Christoph Rieche told colleagues at Goldman Sachs he was leaving to set up iwoca, some of them thought he was crazy. Others were jealous. Ten years later, the second group would appear to have been right: iwoca has now helped more than 65,000 small and medium-sized enterprises (SMEs) gain access to capital. It's building out new products all the time, raising $350m in debt and equity capital along the way. And although Christoph's creative talents may not have come up to snuff for him to have become an architect, the businesses iwoca has helped people to build may end up having an even bigger impact than any structure he may have designed.