1. Every single step MUST be documented clearly and in the correct order. I will follow your instructions step by step on new servers. The servers you will be working on are only for testing and demo. Please put each server's instructions on a separate text file and in the right order.
If documentation is inaccurate or incomplete, the whole project is useless.
2. Install and configure Zabbix 4.0 with Nginx on the two servers and connect them to a MySQL database that resides on another server.
3. On the Load-Balancer, configure Self Signed cert, and document the process of renewing, and ever better if you can automate it with a script.
4. Must turn on SELinux and only keep necessary ports open in the firewall on all servers.
5- Harden all the servers, remove or disable unnecessary functionality and packages, such telnet.
6- Install fail2ban or sshguard and configure Zabbix, Nginix for high load.
7- Follow best DevOps and security practices.
I have already discussed the details with a Freelancer.
Time to be done: 3 hours.