the web performance conference11-12 November 2021, Amsterdam

Talks and speakers is a single track conference with fourteen world-class speakers, covering today’s most important web performance insights. They are selected by our program co-chairs Harry Roberts, Tammy Everts and Tim Kadlec.

Below is our 2021 line-up, which will eventually consist of 14 speakers. Unfortunately we cannot fully guarantee all these speakers will be at the conference—a travel ban between Europe and North America might be in force, for instance. But they all confirmed they want to come if possible.

Pre-register or see our venue

Léonie Watson

Director, TetraLogical, @LeonieWatson

Léonie is Director of TetraLogical; a member of the W3C Advisory Board; co-Chair of the W3C Web Applications Working Group; and until recently was a member of the Accelerated Mobile Pages (AMP) Advisory Committee.

Amongst other things, Léonie is co-organiser of the Inclusive Design 24 (#id24) conference; co-author of the Inclusive Design Principles; and mentor to young people interested in the fields of accessibility and inclusive design. She is also a Microsoft Most Valued Professional (MVP).

Léonie is often found at conferences, talking about web standards, accessibility mechanics, and pushing the boundaries of inclusive design (with existing technologies like SVG, HTML, ARIA, and JavaScript, as well as new technologies like AI and WebVR). She has also written about these things for Smashing magazine,, and Net magazine, as well as on her own site Tink.UK.

In her spare time, Léonie likes reading, cooking, drinking tequila, and dancing (although not necessarily in that order)!

Session topic: Accessibility == Performance

Andy Davies

Independent Web Performance Consultant, @AndyDavies

Andy Davies is an independent web performance consultant who helps companies to make their web sites faster.

Session topic: Third-party scripts

Harry Roberts

Consultant Web Performance Engineer, @csswizardry

With a client list including Google, Unilever, and the United Nations, Harry is an award-winning Consultant Front-end Architect who helps organisations and teams across the globe to plan, build, and maintain product-scale UIs.

A Google Developer Expert, he writes on the subjects of CSS architecture, performance, and scalability at, develops and maintains inuitcss, authored CSS Guidelines, and Tweets at @csswizardry.

Session topic: The <head> tag

Dora Militaru

Developer Relations Engineer, Fastly, @doramilitaru

Dora is a Developer Relations Engineer at Fastly. She cut her developer teeth on building a global news website, and cultivated her compassion by leading data protection and site reliability engineering teams. Working at a tiny kitchen table in London, she dreams of helping others build a faster, more secure, more reliable – a better web – for everyone.

Session topic: Performance Culture

Stoyan Stefanov

Developer Relations Engineer, Fastly, @stoyanstefanov

Stoyan Stefanov is a former Facebook engineer, ex-Yahoo, architect of the YSlow 2.0 performance tool and creator of the image optimization tool. He’s the author of React: Up and Running (O’Reilly), JavaScript for PHP developers (O’Reilly), JavaScript Patterns (O’Reilly), Object-Oriented JavaScript (Packt Publishing), The Book of Speed (online), and a contributor to High-Performance JavaScript (O’Reilly) and Even Faster Web Sites (O’Reilly).

Session topic: Micro Benchmarks

Katie Hempenius

Engineer, Google, @katiehempenius

Katie is an engineer on the Chrome team where she works on making the web faster. Previously she was a software engineer on Google Ad Manager and a senior software engineer at Fitbit.

Session topic: Web Vitals