Build an OTP Flow Your Customers Trust with SMS, WhatsApp, Viber, Email, and TOTP (& Smart Fallback)

If you care about secure logins or safe payments today, you can’t avoid two-factor authentication and one-time passcodes (OTPs). I see many teams still start with SMS for these codes, and that makes sense. It’s simple, and almost every phone can get it. As is the case with every free market though, there are alternatives. […]