The new FT Polyfill service uses the Fastly CDN to provide faster and more reliable access to Polyfills for everyone. But with responses varying by user-agent, it's a caching nightmare. We set out to fix this with a little help from Fastly and custom Varnish VCL.We curated the programme for our fifth Edge conference, the event for people who make the web work, and ran it with the London Web Performance group and Facebook London. It all got a bit heated...FT Labs is an emerging web technologies team at the Financial Times. We experiment with exciting new web technologies and bring the world’s finest journalism to new platforms, technologies and channels. With a focus on using the web to its fullest potential, we deliver user experiences designed to the needs of each user.Smartphones and tablets have brought a revolution in user experience, one we are proud to have brought to the web, and we continue to learn and innovate to deliver a better FT for our readers. At the same time, we