Worked on the Flagsmith/flagsmith repository to address a critical authentication issue affecting Google OAuth functionality in unified Docker deployments. Focused on backend development and configuration management, the solution involved configuring the Cross-Origin-Opener-Policy header using the DJANGO_SECURE_CROSS_ORIGIN_OPENER_POLICY setting. This change restored OAuth compatibility for both unified Docker images and independently hosted frontends, reducing user login failures and support requests. The work was implemented in Python and YAML, with careful documentation of security header changes to support future maintenance. Emphasis was placed on deployment reliability and DevOps practices, ensuring consistent authentication behavior across diverse deployment environments within a one-month period.