The Stripe and Twilio teams collaborated to build a sample application showcasing how to securely collect payment details from customers using Stripe Checkout in setup mode and Twilio Verify for authentication. The application includes two backend implementations, one in Node.js and the other in Python (Flask), with instructions on setting up each. The demo showcases how to run the sample application locally and highlights key features such as client-side phone number formatting and validation, international phone number input field setup, collecting and storing customer payment details securely, sending verification codes via Twilio Verify, checking the verification code, and charging customers using Stripe Checkout. Additionally, the tutorial includes instructions on setting up an international phone number input field, validating the input client-side, looking up the phone number on the server, and listening to Stripe webhook events.