Configure file permissions for WordPress
The most common cause of errors in Wordpress is incorrect file and folder permissions.
Linux
Create a Diffie-Helman Parameter File
This terminal command generates Diffie-Hellman parameters with 4096 bits. This provides good security while still providing acceptable performance.
Disable wp-cron and configure server cron
There is a PHP function built into WordPress which is designed to replicate a cron service, which is activated whenever someone accesses the web site. This is acceptable when only 1-2 people are accessing the site, but as the website usage scales up to dozens of users, this results in an exponential load on the server.
Install and configure fail2ban
Fail2ban is a server-based intrusion prevention daemon which prevents brute-force attacks by scanning log files for authentication errors.