Wikimedia Performance – [[WM:TECHBLOG]]

Profiling PHP in production at scale

We built an efficient sampling profiler for PHP. It runs continually in production on live requests, and generates trace logs and flame graphs.

Web performance case study: Wikipedia page previews

Preview popups are common and requires careful scripting and styling; they can generate useful learning about performance as a reference for other front-end tasks.

How we contributed Paint Timing API to WebKit

The story of how we decided to commission the implementation of Paint Timing API, a feature that lets us observe web performance from an end-user perspective. This web browser feature tells us at what point in time content started to appear on the screen for a visitor.

Measuring the performance of Wikipedia visitors’ devices

We have been collecting microbenchmark scores for over a year. This lets us see the long-term evolution of our audience as a whole. The information gives us an idea of how fast device/operating system/browser environments improve on their own.

Organizing and running a developer room at FOSDEM

For FOSDEM 2020, the Wikimedia Performance Team organized a Web Performance devroom. In this post, they share their experience.

WikimediaDebug v2 is here!

WikimediaDebug is a set of tools for debugging and profiling MediaWiki web requests in a production environment. WikimediaDebug can be used through the accompanying browser extension, or from the command-line. This post highlights changes we made to WikimediaDebug over the past year, and explains more generally how its capabilities work.

Wikipedia’s JavaScript initialisation on a budget

This week saw the conclusion of a project that I’ve been shepherding on and off since September of last year. The goal was for the initialisation of our asynchronous JavaScript pipeline (at the time, 36 kilobytes in size) to fit within a budget of 28 KB – the size of two 14 KB bursts of Internet packets.

Tracking down slow event handlers with Event Timing

We’re taking part in the ongoing Event Timing Chrome origin trial, in order to experiment with that API early and give feedback to its designers.

Performance perception: Correlation to RUM metrics

When we set out to ask Wikipedia visitors their opinion of page load performance, our main hope was to answer an age-old question: which RUM metric matters the most to users? And more interestingly, which ones matter the most to our users on our content.

Performance perception: The effect of late-loading banners

Unlike most websites, Wikipedia and its sister projects are ad-free. This is actually one of the reasons why our performance is so good. We don’t have to deal with slow and invasive third-parties.