I gave Claude the two Excel workbooks that every overhead sign gantry on a South African highway is designed in, to see how far it could get. It pulled the calculations out cell for cell and rebuilt them as a standalone HTML file that gives the same answers. The workbooks were already clever. They drew the elevation live, handed over co-ordinates for AutoCAD, and warned you as you typed. A spreadsheet is not an interface, though, and moving that thinking into one is most of what Ray is. On top of that I added two things the workbook could not do. You tell Ray what your priorities are on this job, and it generates and ranks designs that keep to your rules. It also writes the co-ordinates straight out as a DXF any CAD package opens. The arithmetic is still the brain: the optimiser runs the workbook’s own sums across every size the workbook allows, then sorts the results. What surprised me is that full automation is not the answer. You still want to look at a few of the options yourself, because the compromise each one makes is a judgement call rather than a calculation. The workbooks were built by Raimund Miller for SANRAL. This is not for commercial use and was an exploration of AI tools.