Last month I got a bug report that made me close my laptop and go for a walk. A paying user couldn't log in. Their device was rooted? Not according to them. Custom ROM? Yes. A modern, security-hardened Android build with verified boot and hardware-backed keys. The kind of setup that's arguably more secure than a stock device. My app rejected them anyway. Why? Because somewhere along the way, I had wired up the strictest integrity verdict I could find and called it a day. Classic mistake. If you've shipped any mobile app that talks to a backend, you've probably run into the same trap. Let's dig into why hardware attestation locks out legitimate users, and what to actually do about it. The frustrating problem You add an integrity check to gate sensitive operations — login, payments, key recovery, whatever. The API gives you a verdict. You check the strongest tier. Ship it.…