I love, love, *love, traintimes.org.uk—partly because it’s so useful, but also because it’s so fast. I know public transport is the clichéd use-case when it comes to talking about web performance, but in this case it’s genuine: I use the site on trains and in airports.
Matthew gives a blow-by-blow account of the performance optimisations he’s made for the site, including a service worker. The whole thing is a masterclass in performance and progressive enhancement. I’m so glad he took the time to share this!