CDN acceptance testing for GOV.UK
gdstechnology.blog.gov.uk/2014/10/01/cdn-acceptance-testing
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
We were already some way towards this by version-controlling our CDN configurations and using one-click deployments. What we were missing was automated testing to confirm that our new features worked and that we hadn’t broken any existing features in the meantime. We searched and asked around for existing solutions but couldn’t find any.