In the search for a better user experience metric, we have tried out the upcoming Element Timing for Images API in Chrome.
We use both synthetic and RUM testing for Wikipedia. These two ways of testing performance are best friends and help us verify regressions. Today, we will look at two regressions where it helped us to get metrics both ways.
One of the Performance Team responsibilities at Wikimedia is to keep track of Wikipedias performance. Why is performance important for us? In our case it is easy: We have so many users and if we have a performance regression, we are really affecting people’s lives.