Our detectives are back with the following intel on this WordPress site
The site is using two themes, one child and one parent. The child theme is based on the parent and often custom to the site. The parent theme is Beaver Builder Theme theme by The Beaver Builder Team .
We could identify 4 plugins (there might be more) - bb-plugin , bbpowerpack , Yoast SEO and wp-grid-builder
An example child theme that can be used as a starting point for custom development.