010101 Serious question. Is there such a thing as a website/server that cannot be hacked?
Probably not. 100% security is a myth, no online security is absolute. If some of the biggest and most high tech companies in the world can’t always be bulletproof then nobody can.
The best thing you can do is to make it as difficult and time consuming as possible, which, unless you have something incredibly valuable to them, will usually make someone look for an easier target, because there are a lot of less secure and easy targets out there.
Separate out data so that no one point of entry can access too much, and then have backups, and disaster recovery plans in place so that if it does ever all go a bit wrong you can recover from it.