Developed and delivered a comprehensive User Authentication System for the 666ghj/BettaFish repository, focusing on strengthening security and improving session management. The work involved implementing robust password hashing, enforcing password strength validation, and integrating CSRF protection to mitigate credential-based attacks. Session lifetimes were clearly defined to enhance user safety while maintaining a seamless authentication flow. Using Python and Flask, the developer applied backend development and database management skills to address a registration vulnerability and harden the authentication process. The result was a more secure login experience that reduced risk and improved user trust, all achieved with minimal disruption to users.