I was involved in the whole process from 3d modeling of the idea proposals, figuring out the design, all the way to constructional drawing. The shape of the dunes was 100% designed in a 3d software (Rhino and Grasshopper) and all the thousands of sections were produced automatically in Grasshopper. If this would be done by hand it would be a monumental task, but with digital tools it was just a matter of how we like them to be.  On site the dunes were built with more ease than expected. The reason is that workers are used to building roads where being precise with heights and distances is essential. For them making this was just a more fun task than usual, but fundamentally not that different.