Simon Hiller enhanced authentication and session management across the flarum/flarum-core and flarum/framework repositories by implementing a secure access token lifecycle. He designed features in PHP that invalidate previous sessions and regenerate new ones whenever a new access token is issued, ensuring obsolete tokens are removed from the database to prevent reuse. This approach established a consistent security model between core and framework, improving data integrity and reducing token-related risks. Simon’s work leveraged backend development and database management skills to strengthen the authentication flow, reduce support risk, and lay the foundation for future improvements in session management and token handling.