As a frontend developer, I deal with performance issues every single day. Let's see how it is possible to get an initial picture of frontend performances.
Measuring frontend performances can be very difficult, as there are too many factors involved. This article does not claim to offer the ultimate solution to such a hard problem. Please consider this as a starting point for your studies and insights.
Every time I write a new feature which involves javscript or massive css code, I need to check how much that piece of code impacts performances.
While I was searching for a tool which could retrieve some information about page load timings, I found the great phantomas. This tools is able to collect a huge amount of data regarding a specific URL. Bingo!
Do you think it is too simple? Oh, I love simple things and practices, and you should love them too.
Data phantomas collects may be hard to read, so I wrote a very basic bash script (tested on both Linux and OSX) to get a graph of backend and frontend loading times.
[[ $URLSET -ne 1 ]] && echo "[WARNING] no URL set. Crawling google.com"
echo "[DONE] Report: $( realpath $1 )"
You should consider this as a starting point to measure frontend performances.
Include phantomas in a continuos monitoring system could be a great thing, but it is time consuming and requires a lot of sysadmin knowledge.