Comment by isquaredr

This definitely applies to Google's PaaS offerings. Google App Engine looks like a great solution except your app is now entirely stuck on a constantly changing platform. The drop-in components they offer are constantly getting deprecated and re-architected with no clear upgrade path. For example many of their original drop-in components were custom (Memcache, Taskqueues, NDB) and are now deprecated with no interoperability with the now recommended 3rd party components. If you depended on these components you now are either existing in a precarious purgatory or you need to rip out and replace all uses of those libraries which completely reneges on the PaaS value proposition