Steve Heffernan is the co-founder and product architect at Mux, the developer-first video infrastructure platform, and creator of Video.js - the open-source HTML5 video player powering playback on Amazon, LinkedIn, Instagram, and Dropbox with over 38,700 GitHub stars. Previously co-founded Zencoder (YC W10), the cloud video encoding startup acquired by Brightcove for $30M in 2012. A self-described hacker on video, he is now leading the ground-up rebuild of Video.js v10 at Mux, which raised $105M Series D in 2021.
Dave Rupert is a senior UX engineer at Microsoft, co-founder of the Austin-based web agency Paravel, and co-host of the long-running ShopTalk Show podcast. With over two decades in web development, he is widely recognized for his accessibility advocacy - notably founding The A11Y Project in 2014 - and for open-source tools like FitVids.js and FitText.js. He brings a maker's instinct, a teacher's heart, and a quietly sharp wit to everything he touches.
Jim Nielsen is a design engineer, writer, and curator with 20+ years at the intersection of design and code on the web. He writes the popular Jim Nielsen's Blog covering web development philosophy, design thinking, and the craft of building for the web. He's the founding engineer at Quadratic, co-creator of The iOS App Icon Book (€136K Kickstarter), and maintains the beloved iOS/macOS/watchOS icon gallery sites. A champion of the open web, HTML-first thinking, and the emerging 'design engineer' role, Nielsen bridges the gap between visual design and front-end engineering with rare fluency.
Scott Jehl is a Senior Software Engineer on the Web Performance team at Squarespace, a 20-year veteran of the front-end web who helped define modern responsive and performant design. He authored 'Responsible Responsive Design' (A Book Apart, 2014) and co-authored 'Designing with Progressive Enhancement' (2010), created foundational open-source tools like Respond.js, loadCSS, and Picturefill, and recently led the effort that brought lazy loading to HTML video and audio elements - an official web standard as of March 2026. He speaks globally, teaches online, and believes the web should work fast for everyone, everywhere.