Upgrade Vtiger and Ubuntu Server

Need a freelancer to upgrade a test Vtiger and Ubuntu server environment to the latest versions, then perform a staged production upgrade. The work includes testing the upgrade process, resolving any issues, and ensuring a smooth transition. Experience with MySQL, Vtiger, and Ubuntu is important. The project will be completed in two phases: first the test environment, then the production environment. Right now Vtiger is at 7.1 and at Ubuntu 18.04 LTS. The test environment basically is to move the production to the test environment to work on the upgrades. I know at least getting to 7.5 one can still run Ubuntu 18.04. Then we upgrade the PHP to version 8.1. SO when we get this up to version 7.5, we then upgrade to Ubuntu 20.04. This would allow to get to version 8.0 up to version 8.2 of Vtiger (so at this point PHP 8.1 and Ubuntu 20.04 LTS). Then we upgrade Ubutnu to 22.04LTS and then update to 8.4). Once all upgraded, I will then need to (ourselves) document all the changes we need to make for the customizations we had earlier are intact. We can then move that back once we know things are working to the production environment. Hope this is making sense. I really need someone that will know the error from 7.1 to 7.2 (contacts and leads are blank showing up as an example) and fix that. All errors on MySql were updated and fixed already. So someone that is solid at Vtiger upgrades, PHP upgrades and Ubuntu updates and challenges there. Looking to move this forward quickly. The time between taking the test environment and moving all things to the production envrionment would be a quick move since the production environmnent of 7.1 would not work since Ubutnu was upgarded. Again someone REALLY knowelgable with VTIger, PHP, MySQL and Ubuntu.