Building a Better Web
June 11–12, 2018: Training
June 12–14, 2018: Tutorials & Conference
San Jose, CA

Raiders of the Fast Start: Frontend Performance Archeology

11:00am–11:40am Thursday, June 14, 2018
Performance and UX
Location: 210 A/E Level: Beginner
Secondary topics:  Case study, Web Pillars Track: Performance, Security, Accessibility

Who is this presentation for?

Web developers, UI/UX

Prerequisite knowledge

Familiarity with client HTML, CSS, JS, Basic knowledge of performance best practices is helpful but not required

What you'll learn

How a page is rendered in the browser, Diagnosing page render issues using waterfalls and open source tools, Mobile-specific performance considerations, Improving performance in legacy code, Finding and deleting unused code Making the case to business, Changing performance culture at your organization


There are a lot of books, articles, and online tutorials out there with fantastic advice on how to make your websites performant. It all seems so easy in theory, but applying best practices to real-world code is anything but straightforward. Diagnosing and fixing frontend performance issues on a large legacy codebase is like being an archaeologist excavating the remains of a lost civilization. You don’t know what you will find until you start digging!

Pick up your trowels and come along with Etsy’s Frontend Systems team as we become archaeologists digging into frontend performance on our large, legacy mobile codebase. I’ll share real-life lessons you can use to guide your own excavations into legacy code:

- What open-source tools and metrics we used to diagnose issues and track progress.
- How we went beyond server-driven best practices to focus on the client.
- The tools we built to help find and delete old, unused code.
- Which fixes successfully increased conversion, and which didn’t.

Our work, like all good archaeology, went beyond artifacts and unearthed new insights into our culture. We at Etsy pride ourselves on our culture of performance, but, like all cultures, it needs to adapt and reinvent itself to account for changes to the landscape. Based on what we’ve learned, we are making the case for a new, organization-wide, frontend-focused performance culture that will solve the problems we face today.

Photo of Katie Sylor-Miller

Katie Sylor-Miller


Katie Sylor-Miller is a Staff Software Engineer on the Frontend Systems team at Etsy, where she advocates for and implements frontend best practices in collaboration with product engineers and designers. She is passionate about frontend architecture, design systems, style guides, accessibility, performance, and teaching others. Katie has written about the engineering side of design systems for the Design Systems Handbook, and she created to share her hard-won knowledge of how to get out of your git messes with a bit of humor (and a lot of swears).

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