Scoping reference
Typical duration and team for this path.
A Drupal upgrade is typically structured over **2 to 6 months** depending on complexity. For a Drupal site **with a few custom and standard contrib modules**, plan **2 to 3 months** with a 3-person cell: senior Drupal developer, theme integrator, QA. For a complex site with **20+ custom modules, multi-site, or theme redesign**, plan **4 to 6 months** and 4-6 people. The marginal cost of a Drupal 9 → 10 → 11 upgrade is lower than a Drupal 7 → 10 upgrade (which goes through Drupal 8 or uses migration).