Worked on the basecamp/fizzy repository to address a critical security update by improving CSRF authenticity token handling in a Ruby on Rails backend. The developer replaced deprecated skip_before_action :verify_authenticity_token calls with skip_forgery_protection, aligning the codebase with the latest Rails standards and eliminating deprecation warnings. This targeted fix was applied to controllers managing unsubscribe flows and Stripe webhooks, reducing potential CSRF risks and enhancing reliability for these endpoints. The update, implemented in Ruby, prepared the application for future Rails upgrades and improved maintainability, ensuring that webhook integrations and customer unsubscribe processes remained secure and consistent across the platform.