With NGINX Unit, configuring a new application in an existing production environment does not disrupt existing apps or require configuration reloads. Here are all the relevant commands and configuration from Amanda Bockoven's demo at NGINX Conf 2018.
Amanda Bockoven

NGINX Unit: Updating Apps with 100% Uptime
In this companion post to our video "NGINX Unit: Live App Updates at 100% Uptime", we provide all the background and details for each step so you can follow along as we update an application in a multilingual NGINX Unit environment without disruption or downtime.
Installing WordPress with NGINX Unit
NGINX Unit supports PHP, which is very widely used for web programming. NGINX Unit therefore supports WordPress, written in PHP, and which is a content management system and application used by more than 30% of the sites on the Web. Use this blog post to install Unit and NGINX together with WordPress.