The comparator is born

The idea behind Nada Menos is easy to explain: you build your weekly shopping list and the system tells you where it comes out cheapest, adding up the whole cart — not item by item, but the full trip. What actually matters isn’t “where is rice cheapest,” it’s “where does this entire shopping list make the most sense.”

The first version, the one I put together in a couple of days in late August, already had to deal with something far from trivial, something that weeks later would become the hardest problem of the whole project: the same product is named differently at every store. “Gloria Evaporated Milk 400g” in one catalog and “Gloria Evap. Whole Milk 400 g” in another aren’t, to a computer, obviously the same thing. To a person shopping, they clearly are.

That was the first real question of the project, and the one that would end up setting the pace for the weeks that followed: how do you teach a system to recognize that two things written differently are, on the shelf, the same product?

With that solved halfway, the comparator was already showing something useful. Next was making sure that useful thing didn’t disappear the next time someone opened the app on their phone.