Twilio’s two-factor authentication API, Authy, was launched in 2012 and is now used by Twitch, Gemini, Indeed, SendGrid, Pinterest, VMWare, NameCheap and Transferwise. We’ve learned a lot about how 2FA works in the real world and in this session we will go through our best practices on implementing 2FA into your applications. Do you make 2FA opt-in or mandatory? How do you easily enable 2FA for users? How to failover to another method? All these questions and more will be answered.