Upgrading Drupal from older versions (e.g., Drupal 7) to newer ones (like Drupal 10) involves significant changes: Composer, object-oriented code, Symfony components, and third-party libraries. Despite these shifts, core business logic often remains unchanged. Integrations may differ, using alternative modules or Controller/Service classes over traditional hooks. The strategy in migrating modules to Drupal 8 prioritizes moving functional code rather than rebuilding from scratch. Oliver, renowned for fixed-price, bug-free projects, advocates leveraging existing code for stable, swift software delivery, benefiting developers and clients by avoiding unnecessary rewrites and accelerating robust solutions.