How a dynamic code resolves
2026-09-18 · 5 min read
A QR code — static or dynamic — never contains a destination that can change. What it contains is fixed the moment it's printed. A dynamic code's trick is to encode a short link that we control, and let the destination behind that link change instead of the code itself.
When a phone camera decodes the modules, it opens the short link like any other URL. The redirect service looks up where that link currently points and answers with a 302 — no page load, no app, just a hop to the real destination. The redirect path is intentionally the simplest, most boring code in the whole product: it reads from a cache, never blocks on a database write, and never waits on an analytics write before answering.
The scan itself is recorded asynchronously, after the redirect has already happened, so a slow analytics pipeline can never slow down someone trying to see a menu.
The result is that editing a destination is a single database write against the short link, not a reprint. Every already-printed copy of the code keeps pointing at the same short link; only what that link resolves to has changed.