[fdr]

I saw someone else have a bad reaction to this statement, but I might be to blame for this. See:

http://news.ycombinator.com/item?id=4062983

But let me try to frame it more carefully: at the time (and maybe still) a lot of providers expect you to use special APIs endemic to their platform, and you can't get the real-deal implementation or a drop-in replacement if you want to model the production environment more closely or move off the platform. Even if you get the real-deal implementation, running it may be infeasibly hairy.

Heroku very assiduously tries to avoid this, and there is a downside: we compromise with the problems in existing software that people like to use as-is, and to fix those problems we have to somehow get that software fixed, too.