Final checks and website migration

We are looking for an experienced programmer who will smoothly migrate our website. Website is on an Nginx\PHP-FPM\Percona\MemCache\Varnish dedicated server We need someone to look at present configuration and check if everything is set correctly especially regarding Varnish caching and performance. Many optimization has already been made. So what I would like to ask you to do is: • Write separate vcl file (our provider asked this), possibly a most recent, state of the art one, for each domain (4 domains) under Varnish. • Check performances: sometimes site is fast, other times I am seeing long TTFB also for css, js and images (CloudFlare is the cause?) • Look after the migration, that is change the dns in Cloudflare and make sure that everything will go smoothly. Website is not live so you can do any modification without having to replicate locally. (We are also looking for someone who is able to do some mods to a custom plugin which has been developed by someone who is not anymore available as a freelance. Also looking for someone who will be available in case of need) What past project or job have you had that is most like this one? What questions do you have about the project? Thank you for reading Mauro