はてなブックマーク

Stoyan (@stoyanstefanov) is a former Facebook and Yahoo! engineer, writer ("JavaScript Patterns", "React: Up and Running"), speaker (JSConf, Velocity, Fronteers), toolmaker (Smush.it, YSlow 2.0) and a guitar hero wannabe. Problem As the previous post puts it: A slow CSS prevents the JavaScript following it from executing. And in addition, when the JS following the CSS is inline, it’s naturally syn

Robin Marx is a Web Performance Architect at Akamai Technologies. His main expertise is in network protocol performance, including HTTP/3 and QUIC, which was the topic of his PhD research. In a previous life he was a multiplayer game programmer and co-founder of LuGus Studios. YouTube videos of Robin are either humoristic technical talks or him hitting other people with longswords. If you deal wit

Alex Hamer is software engineer at Tesco, with a passion for building high performance, accessible web applications for the many. For a dynamic web application Time To First Byte (TTFB) can take time, this is certainly the case with the applications I work with. For each request the server receives, in order to respond correctly it could be performing a number of things that can add up; multiple A

How do you take a popular developer platform, free and maybe even open source, and build a strong business around it? Wait a minute, did she just say ‘developer’, ‘open source’ AND ‘business’ in the same sentence? I must warn you – this article is not about web performance insights or web development, but rather […] Largest Contentful Paint (LCP) is a performance metric representing the user exper

Nic Jansma (@nicj) is a software developer at Akamai building high-performance websites, apps and open-source tools. Table of Contents The JS Self-Profiling API What is Sampled Profiling? Downsides to Sampled Profiling API Document Policy API Shape Sample Interval Buffer Who to Profile When to Profile Specific Operations User Interactions Page Load Overhead Anatomy of a Profile Beaconing Size Comp

Stoyan Stefanov (@stoyanstefanov) is an ex-Facebook and Yahoo! engineer, writer ("JavaScript Patterns", "React: Up and Running"), speaker (JSConf, Velocity, Fronteers), toolmaker (Smush.it, YSlow 2.0) and a guitar hero wannabe. Happy 25th birthday CSS! Yes, today marks 25th year of CSS’ existence. Source. Contrary to what some may have you believe, CSS is not the worst. CSS is lovely, CSS is empow

Nic Jansma (@nicj) is a software developer at Akamai building high-performance websites, apps and open-source tools. Table of Contents Introduction What are Beacons? Beaconing Stages Sending Data at Startup Gathering Data through the Page Load Incrementally Gathering Telemetry throughout a Page’s Lifetime Gathering Data up to the End of the Page “Whenever” How Many Beacons? A Single Beacon Multipl

Anthony Ricaud (@anthony_ricaud) is a web engineer helping teams ship efficient products at a sustainable pace. With a broad understanding of web protocols and browsers, he likes to design simple but fast web architectures. Longer page load times Page is unusable until the JavaScript loads and if it does so without any errors Usability, reactivity and accessibility can be lacking without a team wi

Peter Hedenskog (@soulislove) loves Open Source and really cares about the open web. Peter is one of the creators of the Open Source sitespeed.io web performance tools. I hope you didn’t miss the session about The Future Of Core Web Vitals at Chrome Dev Summit 2020. I think it’s great that the Chrome team is open about the metrics and is looking for feedback! When Google Web Vitals first was intro

Gilles Dubuc (@MonsieurPerf) is the engineering manager of the Performance Team at the Wikimedia Foundation. The web performance community has many industry stories about performance perception. But they almost never publish the underlying data and can’t be peer reviewed. As readers, we have to assume that experiments were set up correctly and that the data was interpreted appropriately to reach t

Robin Marx is a Web Performance and network protocol researcher at Hasselt University, Belgium. He is mainly looking into HTTP/3 and QUIC performance, and develops the qlog and qvis tools to make this easier. In a previous life he was a multiplayer game programmer and co-founder of LuGus Studios. YouTube videos of Robin are either humoristic technical talks or him hitting other people with longswo

Matt Hobbs (@TheRealNooshu) is Head of Frontend Development at the Government Digital Service. An experienced frontend developer, he is passionate about using his skills to build accessible and performant user interfaces. Matt makes a point of keeping on top of the latest technology and tools, is interested in all aspects of interface development, and is a keen advocate for best practices. In this

Alessandro Ghedini is a Systems Engineer at Cloudflare helping standardize, implement and deploy network protocols for the Internet. QUIC, the new Internet transport protocol designed to accelerate HTTP traffic, is delivered on top of UDP datagrams, to ease deployment and avoid interference from network appliances that drop packets from unknown protocols. This also allows QUIC implementations to l

Aggelos Arvanitakis (@AggArvanitakis) is a front-end dev that likes huskies and is afraid of bees. Interested in all things perf... CSS-in-JS is becoming a popular choice for any new front-end app out there, due to the fact that it offers a better API for developers to work with. Don’t get me wrong, I love CSS, but creating a proper CSS architecture is not an easy task. Unfortunately though, besid

Matt Hobbs (@TheRealNooshu) is Head of Frontend Development at the Government Digital Service (GDS), a unit of the Government of the United Kingdom's Cabinet Office tasked with transforming the provision of online public services. An experienced frontend developer, he is passionate about using his skills to build accessible and performant user interfaces. He makes a point of keeping on top of the

Michael Gooding (@Michael_G_81) is a performance Geek at Akamai, working with customers, staff and basically anyone that will listen. A premature grumpy old man, slow websites just add to the grumpiness and grey hairs. Read any performance blog or attend any performance talk and everyone will advise you that optimising images is the best place to start (insert the ever present low hanging fruit ph

Stoyan (@stoyanstefanov) is a Facebook engineer, former Yahoo!, writer ("JavaScript Patterns", "React: Up and Running"), speaker (JSConf, Velocity, Fronteers), toolmaker (Smush.it, YSlow 2.0) and a guitar hero wannabe. Let’s talk a bit about keeping tabs on how much CPU is consumed by an application’s JavaScript. And let’s frame the discussion around components – the atomic building blocks of the

Tobias Baldauf (@tbaldauf) helps to keep trivago fast. He creates DevOps tools, image optimization algorithms & speaks at conferences. He's a proud dad, mindful veggy & music lover. Find out more at who.tobias.is tl;dr: JPEG-XR, an image format supported on Internet Explorer and Microsoft Edge browser, gets software-decoded on the CPU main thread alongside Javascript and thereby negatively impacts

Jakub Gieryluk (@__jakub_g) is a web & mobile applications developer, currently working at Dailymotion's video player team, focusing on front-end performance aspects. There are many very good articles out there on how to use new feature X or technique Y or tool Z to improve the performance of your websites. Navigating the labyrinth of modern web performance might be hard though if you’re new to th

Those roundtrips cost time. On a super fast fiber connection it might take just 10 ms for a round trip but on a slow G3 connection that will be easily a small 3 digit number. And those poor clients in Australia who use US servers have to wait a lot. And as I always tell my clients: Bandwidth is not that important for a normal webpage. Latency between the client and the server is. In December 2018

Katie Hempenius (@katiehempenius) is an engineer at Google where she works on web performance. Prefetching is a technique that can be used to achieve near-instant page loads. This technique has been used for decades to speed up hardware and compilers; but it’s only been recently, thanks to the introduction of the Network Information API, that it’s usage to speed up web applications has become prac

Robin Marx is a Web Performance PhD candidate at Hasselt University, Belgium. He is mainly looking into HTTP/2 and QUIC performance, and maintains the TypeScript QUIC implementation Quicker. In a previous life he was a multiplayer game programmer and co-founder of LuGus Studios. YouTube videos of Robin are either humoristic technical talks or him hitting other people with longswords. QUIC and HTTP

We are talking a lot about performance, how it can be improved, which tools to use for performance improvements but less about how to keep reached performance on a proper level. So, let’s take a look at tools which can help you to do so. Size Limit ai/size-limit Size Limit is a tool to prevent JavaScript libraries bloat. With it, you know exactly for how many kilobytes your JS library increases th

Addy Osmani (@addyosmani) is an Engineering Manager working with the Chrome and Web Developer Relations teams at Google. He's written open-source books like 'Learning JavaScript Design Patterns' and 'Essential Image Optimization' and created open-source projects like Yeoman, HNPWA and Critical. You can find more of his work on web performance over on his Medium channel. Tinder recently swiped righ