Framework: Device routing — a 4-branch decision tree

Device routing fails when it only checks 'mobile vs desktop'. Split deeper.

— Branch 1: OS — iOS and Android often have different best offers; route them separately, not as one 'mobile'.
— Branch 2: Connection — Wi-Fi vs carrier (mobile IP). Many mainstream/pin-submit offers require carrier; detect and route them there.
— Branch 3: Browser — in-app webviews (Instagram, TikTok, Facebook) break some redirects; route to webview-safe offers.
— Branch 4: Desktop — split by OS only if you run software/extension offers.

Step: parse the user-agent and the IP's connection type at the router, before applying geo.

Device rules run AFTER geo in most platforms — confirm the order in yours, or carrier offers leak to Wi-Fi users.

Review the device tree monthly as offer requirements change.