Too Long; Didn't Read
Nginx acts as a load balancer between services, you can track the request time between all of them. There are several instances where the application is running and where Nginx is used as a balancer. Not many tools are able to collect request time, and this was a very priority in our case. After a little googling, I found an [nginxlog-exporter] tool that displays metrics on a specific port by default, 4040. Based on the documentation, it’s clear that you can supply the exporter as a deb package, which is quite suitable for your small project.