A QR code can look perfect in your browser and still fail on a printed flyer behind glass, on a wrinkled shipping label, or under a flickering streetlight at dusk. When you treat generation as a one-step drop into a designer, you skip the constraints that decide whether the code is actually scannable in the field. This article walks through the engineering decisions that show up after you hit "download" — the ones that decide whether your audience scans cleanly or gets a "Could not read code" er...