What questions should I ask a WMS vendor in a demo?

This is the question every WMS selection guide answers. There are good lists out there. The problem isn't the lists. It's where the questions come from.

Every question a founder generates for a vendor demo originates from inside a buyer-only frame of reference. That's not a failure of preparation — it's the only frame a buyer has ever occupied. The frame determines which questions feel important, which vendor answers feel satisfactory, and which risks don't register as risks because the buyer doesn't know to look for them. Vendors are specifically designed to be evaluated by buyers. The questions that come naturally from a buyer's seat are the questions vendor demos are built to satisfy.

The questions that actually expose fit problems come from the other side of the table. Where will this system require workflow customization that your support team will quietly bill against later? Which capabilities you just demoed are full product and which are roadmap? When this implementation gets complicated, who on your bench is actually assigned, and how many concurrent projects are they on? These aren't smarter versions of buyer questions. They come from having watched implementations go sideways from inside the vendor and from inside the implementation team — knowing which polished demo answers predict which downstream problems.

A founder running solo can be handed a list of those questions and ask them word-for-word. The vendor still answers from inside a frame the buyer doesn't share. The follow-up questions that would catch the deflection don't get generated, because the founder doesn't have the pattern recognition that produces them. The frame itself is the gap. A better list of opening questions doesn't close it.