We quite often post articles about interesting things we’ve seen in the course of our work: snapshots of edge cases or dire examples of failures to optimise.
So, for a bit of a change, we thought we’d give you a quick run-through of a typical engagement. In case you’ve always wondered what went on in a load test, here’s an outline of some work we did recently…
Imagine that you’ve set up some performance monitoring on your website. You’ve noticed that load times seem to vary quite a bit from one test to the next, and you’re not sure why. It’s a bit of a worry. You have performance targets to meet, and the slower tests are taking your monthly average over the limit.
You’re concerned about the fluctuations in load time, and you’d like to find out what’s causing them.
In the course of your investigation, you come across one disturbing possibility.
Have you ever looked at your website on a mobile phone and noticed that some of the images look a bit different? Perhaps they seem blurry or grainy compared with how they appear on a laptop or desktop.
It’s almost as if, at some point on their journey between server and browser, someone has taken those images and recompressed them…