replying to myself - the client at the bottom had a "move to AWS" mandate from management, they moved, then found out that at least some of their use cases weren't supported. As silly as it sounds, research a tool before you commit to it. Some things are certainly not discoverable until midway in to a project - life happens - but moving ops to AWS in ... 2014, 2015, 2016 - there's enough "known" caveats and gotchas already documented that basic things shouldn't be a surprise. The cost of working around those gotchas often surpasses any first year savings from a migration, but as I've learned - "that's someone else's budget" is sometimes a valid excuse (from some perspectives anyway - as a shareholder, I wouldn't want that justification).