[tdavis]

I think bad_user covers most of it, (although to be fair misses the mark on some things too; there is no 5000-entity limit per query if you use the query as an iterator rather than calling fetch(), which is a much better idea generally) but it's not that deployment itself is difficult--that's the only easy part, frankly.

What's tedious is development, due to all the restrictions and extra concerns necessary. They may make total sense for Google but make zero sense for the rest of the world's applications.

As one simple example, everything you need to be consistent must be handled in a manual transaction but transactions are slow and prone to collisions with insane time-outs (e.g. a request takes 45 seconds because a transaction couldn't commit the first time). Don't even get me started on cross-entity transactions or parent/child relationships, both of which you can use to completely destroy all semblance of performance in an application. Something you take for granted every day on any other platform (transparent, fast consistency guarantees) is of constant consideration and concern on AppEngine--and the APIs presented for it are pedestrian.

These are not intractable problems; none of AppEngine's shortcomings are, really. But the huge number of man-hours spent dealing with its terrible APIs, restrictions, and astounding pre-optimization requirements are hours that could have been spent self-managing a much more user-friendly platform.