User registration with email verification is a better user verification system and this project demonstrates it. With Spring Boot 3 and Spring Security 6, the spring-email-verification app is built as the backend and the frontend is built with react as a separate project named react-email-verification(check my repos).

user verification system created with Java that reads a CSV containing user credentials, prompts users to enter login credentials, and provides feedback on their login status

Track expenses, savings, lendings, etc at one place. using JWT tokens to verify the data integrity. Using email OTP validation to verify email.