I have built ad-tech systems which get large amounts of traffic and continuous hacking attempts/DDOS attacks. In 10 years, the servers have never been hacked.

I have built ad-tech systems which get large amounts of traffic and continuous hacking attempts/DDOS attacks. In 10 years, the servers have never been hacked. I went to the trouble of enabling SELinux and locking things down. Not sure if it was all needed, but I can't say I am unhappy I did it. After setting things up, it hasn't been a problem.