I think Quay is more like GitHub for Docker, Shippable is more CI/CD for Docker, and the Memcached service is definitely not a PaaS. Along with the book, 4/10 of them are not like a PaaS for Docker.
From memory there are presentations or blog posts by engineers at Ebay, Mailgun, Cloudflare, Spotify, RelateIQ, Atlassian, Baidu, Yandex, etc.