DirectTrust.org was originally created in SquareSpace but was not mobile-friendly or very modern. It needed to be updated and moved to a new platform that had more flexibility while maintaining good security. They have many users and many editors so the site needed to be easy to maintain.
One challenge was the sheer size of the site but another was the number of users (over 500) that needed to be imported in bulk.
Once we decided on WordPress, we started investigating different themes and chose one that was flexible and secure, as well as mobile and user-friendly. Then we had to work on a way to import the users in bulk (thank you to a plugin). This worked pretty seamlessly and users were sent emails to notify them of the change.
Our host, InmotionHosting, was a huge help in migrating the site. Kudos to them!