TL;DR: For a US/EU healthtech signup flow, use a hosted SMS OTP service to generate, expire, and verify codes, but keep consent evidence, attempt limits, geographic policy, and spend circuit breakers in the application. The decisive requirement is not how quickly a text arrives; it is whether an...
Source: [Dev.to](https://dev.to/godfreysterling1574/sms-otp-api-explained-healthtech-saas-login-code-verification-controls-3efo)