[makerops]

Actually talking to a taco truck owner >>>> Random Guessing about a domain you have little knowledge of.

But, what I think his point was, make a list of things that taco truck owners spend time/money on.

Marketing, food ingredients, labor, gas, deciding where to post up for the lunch rush, food prep time, etc.

Pick something out of the list that you have braninstormed, and drill down into how can software solve this problem for less money or in a positive ROI money for time tradeoff, than the current solution (I think in a lot of areas of industries, it will turn out, that you just can't).