Programatically Performant, capturing web performance data using JavaScript

Earlier in the year I spoke at Halfstack Online, an online version of the Halfstack London conference I have spoken at for the past 5 years. The title for this talk is Programatically Performant, a talk all about how as developers we should focus more time on capturing web performance metrics from our site so we can make informed decisions on how to improve using data. Having given the talk I realised how it might be useful to write a blog post on this topic as well, and that was how this post was born.

The different kinds of data

Web performance data about your site can be split into two kinds of data

The first type of data we will collect is synthetic data. Synthetic data, as the name suggests is data captured in a lab like setting, usually this means running your test from a server in a enviornment that has a consistant internet connection. Quite often as developers we will run these in platforms like AWS or Google Cloud Platform.

The second type of data we will look at collecting is Real User Metrics, this is often abbreveatied as RUM. Real User Metric are captured in the users browsers and reported back to your server using JavaScript.