migration of Alfresco community from 4.2 to 6.2

Good morning, we need to migrate an old Alfresco document community 4.2 to latest version, our solution includes several customizations, details of the project will be provided later in a specific document, at the moment you can just place a bid to show your interest. We need proven experience with Alfresco and its customization, so your bid will be considered only if you present previous experiences and case studies with this platform.