Marcel Horner enhanced the DefectDojo/django-DefectDojo repository by developing a backend feature that enforces HTTPS redirects after social authentication, addressing a key security concern in login flows. He introduced the SOCIAL_AUTH_REDIRECT_IS_HTTPS setting, implemented in Python, to ensure all post-login redirects use secure connections. Marcel also updated the project’s Markdown documentation, providing clear guidance for configuring this setting across different environments. His work focused on security best practices and improved deployment clarity for operators and end-users. While the contribution was limited to one feature over a month, it demonstrated depth in backend development and attention to secure authentication workflows.