performance.now() 2018
2018-11-08..2018-11-09
Amsterdam, Netherlands
[performance.now() 2018, performance.now() 2019, performance.now() 2022, performance.now() 2023, performance.now() 2024, performance.now() 2025]
who it's for
frontend developers, web performance engineers, frontend architects, site reliability engineers, devops engineers, engineering managers
topics
JavaScript main-thread offloading; User Timing and Long Tasks; web font loading strategies; QUIC and HTTP evolution; preload and resource hints; image compression and progressive JPEG; service worker app-shell caching; RUM and synthetic metrics; HTTP headers and Server-Timing; resource loading diagnostics; interaction frame-budget debugging
| title | author | length |
|---|---|---|
| It's My (Third) Party and I'll Cry If I Want To | Harry Roberts | 47m |
Shows concrete failures and fixes: a tag manager outage blocks rendering for ~80–90 seconds (Chrome timeout ~80s) and can freeze pages; WebPageTest plus… | ||
| Fast but not Furious: Debugging User Interaction Performance Issues | Anna Migas | 44m |
Argues that perceived performance is about post‑load interactions and shows concrete debugging steps: measure frames with Chrome Performance and Layers and… | ||
| How I optimized my JavaScript sheet music rendering engine | Adrian Holovaty | 50m |
Soundslice is a JavaScript canvas renderer that trades SVG for raw bitmap speed, uses a windowed canvas to redraw only the visible rectangle, and subsets a… | ||
| The Five Whys of Web Font Loading Performance | Zach Leatherman | 47m |
Default WordPress theme loads five font files totaling 100 kilobyte of web fonts and on 3G shows 3.3 seconds first render and visually complete at 5.7s with… | ||
| Down the line: Evolving HTTP and making things QUIC | Natasha Rooney | 51m |
QUIC moves HTTP off TCP onto UDP to avoid TCP head‑of‑line blocking, implements multiplexed streams, built‑in congestion control and ACK/timer loss detection… | ||
| Headers for Hackers | Andrew Betts | 46m |
Shows which headers actually matter and which are cruft: HTTP Archive finds CSP on 2.9% of sites, Strict-Transport-Security widely used, and worthless headers… | ||
| How I learned to stop worrying and love UX metrics | Tammy Everts | 48m |
Argues there is no single “unicorn” metric and demonstrates concrete options, using SpeedCurve, WebPageTest, synthetic and RUM data, Lighthouse and custom… | ||
| The Long-Tail of Performance | Tim Kadlec | 53m |
Examples and analyses show the long tail drives real user harm: median site weight is median 1.5 MB while the 90th percentile 5.7 MB users suffer far worse… | ||
| Past, Present and Future of Resource Loading | Yoav Weiss | 50m |
Resource loading is slow because of measurable steps — DNS/TCP/TLS handshakes, server TTFB (often ~450 ms), slow start (initial congestion window ≈14 KB)… | ||
| Image Optimization | Kornel Lesiński | 47m |
JPEG stores frequency coefficients instead of pixels and progressive JPEG can render a full-feeling image from the low frequencies first. Serving the first… | ||
| Raiders of the Fast Start: Frontend Performance Archeology | Katie Sylor-Miller | 50m |
Etsy focuses on the listing page and measures DOMContentLoaded and start render, uses webpagetest.org, Chrome Coverage and an AST-based logger called Vimes… | ||
| PWA Challenges | Jason Grigsby | 51m |
Concrete results and gotchas: a PWA is simply HTTPS serviceworker manifest and service workers deliver big first‑paint gains for repeat visits but are hard to… | ||
| Move Fast & Don't Break Things | Scott Jehl | |
Webpage performance is a high priority for any site of scale today, but it can be easier to build a fast site than it is to maintain one. As a site's features… | ||
| Building a Foundation for Performance | Michelle Vu | 47m |
Pinterest serves ~250 million MAU and >1M requests/sec and builds a performance stack that proves results: synthetic regression tests plus RUM, dashboards and… | ||
| The Latest in Metrics & Measurement | Paul Irish | 54m |
Defines and compares concrete metrics and collection tools: First Contentful Paint as first non‑white paint, First Meaningful Paint waiting for webfonts… | ||
| Make JavaScript Faster | Steve Souders | 41m |
Argues JavaScript is the biggest bottleneck: JavaScript consumes twice as much CPU as loading layout and rendering combined, backed by HTTP Archive data across… | ||
| nothing matches | ||