performance.now() 2023
2023-11-02..2023-11-03
Amsterdam, Netherlands
[performance.now() 2018, performance.now() 2019, performance.now() 2022, performance.now() 2023, performance.now() 2024, performance.now() 2025]
who it's for
web performance engineers, frontend developers, React developers, engineering managers, site reliability engineers, developer advocates
topics
browser benchmarking techniques; main thread long task decomposition; React application performance; JavaScript bundle size reduction; resource loading strategies (preload/priorities); HTTP cache rules and policies; compression dictionaries (Brotli/Zstd dictionaries); real user monitoring noise reduction; Largest Contentful Paint diagnostics; China-specific web performance and routing; performance for low-end devices and the digital divide; page navigation and transition performance
| title | author | length |
|---|---|---|
| performance.now() 2023 compilation | 01m | |
Compilation of the 4th performance.now() conference recorded November 2–3, 2023, presenting all sessions compiled as a single upload; session content itself is… | ||
| Pushing Pixels | Mark Zeman | 54m |
Argues that delivery should target visible pixels not pages, claiming an SPA shoved hundreds of resources so a hero image appears ~10.5s while static HTML… | ||
| Benchmarking Browsers | Bas Schouten | 51m |
A cross‑vendor benchmark called Speedometer 3 defines concrete workloads (updated 2do MVC, charts, editors, news-like page navigation) and a joint governance… | ||
| Breaking Down Long Tasks | Nishu Goel | 44m |
Metric-level claim: Interaction to Next Paint (INP) replaces FID in March 2024 and measures worst interactions not just the first; field data shows p75 has 36%… | ||
| Optimizing your React Application | Keerthana Krishnan | 51m |
Claim: React sites show worse real-user web vitals than peers, dropping from 36% to 34% “good” LCP/CLS rates among the top 1M. Evidence: field RUM analysis… | ||
| The Unbearable Weight of Massive JavaScript | Ryan Townsend | 53m |
Claims a 55,000-line JavaScript codebase shrinks to 650 lines and time‑to‑interactive drops from about 12s to ~3s by prioritizing progressive enhancement and… | ||
| Creating Performance Impact in a Changing Tech Landscape | Tammy Everts | 50m |
Argues for concrete moves: identify the critical rendering path and focus on pages that drive revenue, lean on synthetic + RUM (WebPageTest, SpeedCurve) and… | ||
| Resource Loading at the Cutting Edge | Robin Marx | 51m |
Browsers disagree about real priority behavior (fonts are highest in Chrome but low in Firefox), HTTP/2 uses a complex prioritization tree while HTTP/3 carries… | ||
| Bridging the Digital Divide using Web Performance | Matt Hobbs | 48m |
Focuses on measurable fixes not slogans: gov.uk went mobile first in 2012 and handles spikes of ~88,000 requests per second with a CDN that achieves ~99% cache… | ||
| Noise Canceling RUM | Tim Vereecke | 46m |
Real User Monitoring contains measurable noise: on aggregated data and a 6M‑monthly‑visit site HVN reduces about 22% total noise down to 78% human visible… | ||
| Challenging Assumptions About LCP Best Practices | Estela Franco | 43m |
Data show LCP remains the weakest Core Web Vital and images are the most common LCP element, with surveys like Web Almanac saying almost one in five mobile… | ||
| Cache Rules Everything | Harry Roberts | 52m |
Only two headers actually solve HTTP caching: cache-control and ETag; remove clutter like Pragma, Expires and Last-Modified. Use directives you can reason… | ||
| Decoding the Web in China for Peak Web Performance | Jodie Chan | 43m |
Global web best practices often fail in China because latency, blocked third‑party resources and packet loss make sites time out or show blank filmstrips… | ||
| Compression Dictionaries | Patrick Meenan | 52m |
Claims that HTML and resources shrink upwards of 90% for some sites and that week‑over‑week JS updates can be 96% smaller are backed by concrete numbers… | ||
| From Here to There | Tim Kadlec | 48m |
Crowdsourced experiments turn into concrete wins: Largest Contentful Paint lands in multiple browsers, WebPageTest and SpeedIndex seed hero-image timing work… | ||
| performance.now() 2023 is done! | 01m | |
Wrap-up of the event lists concrete outcomes and followups: 40 talks and 12 live demos are available now for Early Adopter members, with regular subscribers… | ||
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