upgrade typo3 6.7.20 to 12.4.3

I am looking for a freelancer to upgrade my existing Typo3 6.7.20 version to 12.4.3. The upgrade is a major one and I am not sure if data migration is needed to facilitate it. I may also need additional assistance if any issues arise during the upgrade process. The freelancer should have experience working with the Typo3 platform, and be knowledgeable about its configurations and processes.