When web performance experts gather, it’s a moment for pushing boundaries, sharing advanced strategies, and forging solutions for tomorrow’s challenges. Performance.now() 2024, held in Amsterdam on November 14-15, was no exception. The Uxify team had the opportunity to attend and contribute to this impactful event, diving into topics and trends shaping the future of web performance. Here’s a recap of the essential insights from three full days of learning and collaboration.

Pre-events: WebPerfDays Unconference and perf.sync

Before the main event began, performance.now() 2024 kicked off with an engaging day featuring two pre-events: WebPerfDays Unconference at Google’s office and Mozilla’s perf.sync. Both offered unique opportunities to connect with like-minded professionals and spark new ideas around web performance.

WebPerfDays Unconference

Hosted at Google’s Amsterdam office, the Unconference was an open forum for sharing knowledge, exchanging insights, and brainstorming creative solutions to web performance challenges. The attendees split into three groups, each delving into different themes and topics designed to push the boundaries of current practices.

Here’s a snapshot of what was discussed:

• Performance debugging and evaluation tools: Participants didn’t just share their favorite tools; they also proposed new ideas directly to Google’s team for potential implementation. The openness of Google’s representatives to these suggestions added an exciting dimension to the discussion, sparking hope for practical enhancements in the future.

• Better outreach to developers and users: The group highlighted the value of improving documentation and exploring new methods to educate developers about performance optimization.

• Interaction to Next Paint (INP): The discussion on INP extended to Google Tag Manager (GTM) and its potential to negatively impact INP if misused. Attendees explored practical steps to mitigate this, emphasizing the importance of configuring GTM correctly to minimize its impact on performance metrics.

• Single-Page Applications (SPAs): The challenges of optimizing SPAs were explored, with attendees offering ideas to tackle their unique performance hurdles.

• Gaps in APIs: The group discussed missing APIs that could empower developers to optimize web performance more effectively.

The relaxed yet focused atmosphere encouraged open conversation and collaboration, making it a standout part of the pre-conference experience.

Mozilla’s perf.sync

Later, Mozilla hosted their perf.sync pre-event, where attendees were treated to valuable insights and practical tips on web performance. The discussions offered a wealth of ideas to inspire developers and attendees, helping them refine their approaches to performance challenges.

This gathering didn’t just provide information—it inspired action. Attendees left with fresh perspectives and strategies to implement, demonstrating the strength of community-driven knowledge sharing.

These events set the tone for the main conference, fostering a spirit of collaboration and innovation. They reminded us that web performance isn’t just about individual tools or techniques—it’s about coming together to create a faster, better web for everyone.

Day 1: Kicking off with a knowledge fest 🚀

The opening day was nothing short of incredible. Packed with wisdom and sprinkled with humor, every talk was a masterclass in web performance. Here’s what stood out to us:

Tammy Everts: Web performance landscape in 2024

Tammy Everts highlighted pressing challenges, including growing JavaScript and video file sizes, and their impact on page speed and overall user experience. By examining how Core Web Vitals correlate with engagement metrics, she reinforced the need for a more strategic approach to balancing performance and content richness.
📌 Tammy Everts' Web performance landscape in 2024 Slides

Harry Roberts: Site-speed that sticks

Harry nailed a sentiment we all share: Lab data is great for testing but falls short when it comes to monitoring real-world performance. He emphasized the importance of setting precise performance KPIs, creating backstops and budgets, and focusing on real-world data from RUM instead of synthetic testing alone. His insights served as a practical guide for aligning performance goals with business outcomes, making optimization a sustainable priority.

Eric Bailey: Accessible is performant

Eric Bailey’s talk reminded attendees that accessible design is essential not just ethically but for performance. He championed semantic HTML and shared best practices for reducing DOM complexity, minimizing cognitive load, and avoiding performance-degrading accessibility overlays. These foundational steps ensure a site’s performance aligns with inclusive design principles, creating a seamless experience for all users.

Paul Calvano: Performance mistakes

Paul brought humor and humility with his list of common performance pitfalls. Calvano shared a relatable and data-driven look at common performance mistakes that continue to slow down websites despite their simplicity to fix. From overusing lazy loading on key images like the LCP element to preloading unnecessary resources and mismanaging compression settings, Paul highlighted mistakes that can have an outsized impact on load times. He also stressed the importance of prioritizing resource hints correctly, avoiding redundant scripts, and ensuring third-party resources don’t bloat site performance. His checklist, based on HTTP Archive data, provided teams with actionable steps to address these frequent issues, reinforcing that even small adjustments can lead to substantial performance gains.

📌 Paul Calvano's Performance mistakes Slides

Anna Migas: Thinking beyond Core Web Vitals

Anna Migas challenged the audience to consider the needs of users who fall outside the typical performance metrics—especially those on lower-end devices and with limited connectivity. She emphasized that Core Web Vitals (CWV) are crucial but often serve only the “top 75%” of users, leaving a significant portion underserved. Migas advocated for strategies like progressive enhancement and network-aware content delivery to ensure accessibility for all users, regardless of device or connection speed. By highlighting case studies from regions with high latency and mobile-first markets, she underscored the ethical and practical importance of designing for inclusivity. Her insights pushed teams to adopt a holistic, user-first mindset that goes beyond CWV to create a universally performant web.
📌 Anna Migas' Thinking beyond CWV Slides

Jason Grigsby: Third party woes

Jason Grigsby explored the ongoing challenges that third-party scripts pose to web performance. Noting that about 45% of requests on many sites come from third parties, he urged developers to assess each script’s necessity. Grigsby highlighted tools like Partytown and Zaraz, which can help manage these scripts by offloading them to web workers or the edge, though with certain trade-offs. His call to action included establishing performance clauses in contracts with third-party providers to ensure accountability and minimize site speed impacts.

Alex Russell: Reckoning: Frontend's Lost Decade

Alex Russell delivered a critical look at the state of frontend development, arguing that the web platform risks losing ground to native applications. He emphasized that while mobile OS constraints play a role, the web community has also contributed by adopting practices that compromise performance. Russell challenged developers to prioritize user-centered practices and rethink their reliance on frameworks that may degrade user experience. His insights underscored the need for a return to web fundamentals to keep the platform competitive and resilient.

Breaks that were anything but ordinary

The energy didn’t dip during the breaks—in fact, that’s when some of the most exciting moments happened:

1. Live Talks with Henri Helvetica: Our co-founder, Georgi Petrov, joined Henri Helvetica’s live talks, sharing how Uxify is helping redefine web performance optimization through AI-powered solutions and leveraging browser capabilities and AI technology.

   

   
   

2. Google’s Live Demo: The team participated in an exclusive live demo by Tze Yi Tan and Barry Pollard, where Google showcased new features and innovations for Chrome’s Performance tab. The duo provided direct feedback, helping shape tools that developers worldwide will soon use to optimize their workflows.

Day 2: Continuing the Journey of Web Performance 🔥

Day two was just as inspiring, featuring talks that pushed the boundaries of what’s possible in web performance. Here’s a recap of the day’s gems:

Tim Kadlec: In the blink of an eye

Tim Kadlec delivered an impactful keynote on the relentless demand for speed in digital experiences. He emphasized that while Core Web Vitals (CWV) have been transformative, they should be seen as foundational, not as end goals. Kadlec introduced Speculation Rules as a powerful new tool to optimize navigation timing, streamlining user journeys by predicting and preloading critical resources. He underscored the importance of real-user metrics to keep pace with users’ ever-growing expectations, particularly as younger users accustomed to instant speeds raise the bar. His session was a call to action for continuous, data-driven performance improvement, pushing teams to stay proactive in refining their approach.

Jack Franklin: DevTools deep dive

Jack Franklin captivated the audience with an in-depth exploration of DevTools, showcasing both recent updates and lesser-known features that can dramatically streamline performance diagnostics. He emphasized the power of the Performance Panel, which now allows developers to link localhost sessions to live URLs for real-user metrics, providing invaluable insights by bridging development and production data.

Franklin also highlighted new annotation capabilities that enable developers to document key moments within traces, improving collaboration and making it easier to identify bottlenecks. Additional tools, such as network request blocking and flame chart filtering, simplify the debugging process by allowing developers to isolate and analyze their own code, hiding framework overhead when needed.

One of the most exciting revelations was DevTools’ upcoming AI-powered insights. These features will analyze traces to provide actionable suggestions on performance optimizations, potentially transforming how teams approach debugging and improvements. Franklin's insights encouraged attendees to explore the full potential of DevTools, recognizing it as an evolving toolkit that can drive faster, more efficient performance enhancements.

Mandy Michael: Font performance strategies

Mandy Michael delved into effective strategies for optimizing web fonts, and balancing design aesthetics with performance. She highlighted techniques like using WOFF2 format for smaller font files, preloading critical fonts, and leveraging variable fonts to reduce load times. Mandy also emphasized CSS properties like size-adjust to maintain visual consistency between system and custom fonts, helping to minimize layout shifts. Her insights offered practical steps for achieving fast, visually appealing typography without compromising speed.

Erwin Hofman & Karlijn Löwik: INP case studies

The fantastic duo from RUMvision (Erwin Hofman and Karlijn Löwik) presented a standout session on optimizing Interaction to Next Paint (INP), showcasing real-world examples that illustrated both the challenges and impactful solutions for this critical metric. They shared compelling insights from case studies where companies achieved significant INP improvements by taking a targeted approach, such as refining third-party scripts and removing unnecessary code.

In one example, a client reduced INP by 36% after analyzing and optimizing third-party data usage, while another company achieved a 77% improvement simply by eliminating a single outdated script that caused long delays. Hofman and Löwik emphasized that Speculation Rules can be a powerful tool in INP optimization, as pre-rendered pages reduce initial load tasks and speed up user interactions.

Their presentation underscored the importance of assessing each element on a page, encouraging developers to question the necessity of every script and resource. The session reinforced INP as a vital metric for enhancing user engagement, urging teams to adopt proactive strategies for monitoring and continuous improvement.
📌 RUMVision's summary and INP case studies

Jason Williams & Paul Williams: Bloomberg becomes browser

Jason and Paul Williams shared Bloomberg’s rigorous approach to web performance, where speed is mission-critical. They introduced Container Timing, a custom metric for tracking complex interactions, and highlighted Bloomberg’s contributions to web standards like CSS Grid. Their meticulous instrumentation and monitoring showcased what’s required to maintain high performance at scale, offering valuable insights for teams managing complex applications.

Daniel Roe: Unpacking bundling

Daniel Roe explored how strategic bundling can transform JavaScript frameworks from performance liabilities into assets. He highlighted bundling techniques to update or remove specific payloads, allowing users to load only essential code. Roe also discussed the selective inclusion of third-party scripts in the build process to control load order and reduce runtime impact. Tools like Nuxt’s optimization capabilities, he explained, help streamline CSS delivery and minimize unused styles. His session underscored that effective bundling is an ongoing process, critical for delivering a lean, efficient user experience.

Annie Sullivan: Aiming for the stars

Annie Sullivan closed the conference with an inspiring session on setting a “North Star” for web performance. She emphasized the importance of defining critical user interactions and using real-user monitoring (RUM) to track these metrics. Sullivan outlined a strategic approach, encouraging teams to aim beyond Core Web Vitals as baseline goals and instead focus on continuous improvement through targeted experiments. Her advice on using RUM data to pinpoint bottlenecks and validate changes served as a practical guide for teams looking to drive long-term, user-centered performance enhancements.

Uxify @Google’s Help Desk

Our team stayed hands-on throughout Day 2 as well. Simeon Totev and Ivailo Hristov were part of Google’s Help Desk, answering questions and discussing web performance topics with other attendees. Their expertise helped spark meaningful conversations and shed light on pressing performance challenges.

Our takeaway: A community fueled by innovation and collaboration 🤝

Performance.now() isn’t just about learning—it’s about connecting, sharing, and collectively pushing the web forward. From actionable strategies to bold ideas, this year’s event was a powerful reminder of why we do what we do at Uxify.

Here’s to another incredible year of performance.now()—already counting down to 2025! 🎉

Let us know your favorite moment from the conference, or reach out to see how Uxify can help turbocharge your web performance! 🚀