[pbiggar]

App Engine is a pain in the ass, and I wouldn't recommend it to anyone. Heroku is so simple to use that I've many times felt that someone needs to build a Heroku for Python.

The only thing really wrong with App Engine is the datastore:

- It's very different than anything you've come across before - The docs are not sufficient for it's complexity. You end up having to read lots of blogs and watch lots of videos to figure it out. - It is ridiculously difficult to learn (one of the hardest things I ever had to do) - Important parts of your stack won't work, like Admin - You can't just add the fields you like to an object. Instead you need to meticulously plan _how_ your data is going to be accessed. This is exactly the wrong thing for a startup, since you can't get up and running fast. - You can't iterate fast, because any schema change is very risky and very slow. - If you don't get everything exactly right, your app will be very slow. - There isn't much in the ecosystem.

By contrast, none of these are true for Heroku.

There are some things that are pretty good about App Engine:

- the tools are pretty good. Not as good as Heroku, but good. - the billing is spot on. They give you about $1 per day of free stuff, which can maintain a site with hundreds of thousands of users. And it's pretty cheap from there on. - They scale it automatically. On Heroku, it's really hard to tell how many "dynos" (whatever the hell that is) you need, except by trial and error. I would expect that nearly all Heroku apps are overprovisioned. App Engine just nails the scaling - it happens automatically, and you specify a maximum amount to pay per day, with lots of different dials to control it more precicely if you like.

I hope Djangy takes the best of both worlds.

[mshafrir]

While I do agree that the App Engine datastore does require for some planning above what you're used to from a traditional RDBMS, I think it really just reflects a learning curve that comes with any new technology: as you use it more often, you get better at it. I think calling App Engine a pain in the ass and that you wouldn't recommend it to anyone is a bit over the top.

[pbiggar]

No, I truly meant it. Everything related to the datastore is difficult and tedious. Goodbye to incremental development, goodbye to knocking out a feature in an hour. Every single change you make has to be planned.

Adding a field to an "object"? Where do you use that object? Is there somewhere that you don't use that field which becomes too slow?

How are you going to migrate that new field? There aren't tools to help you migrate. Generally, you have to change to an Explando, add the field, load every single object from the datastore, then save every object back to the datastore.

These are two examples off the top of my head. Every change you want to make in App Engine has similar questions raised. I really did mean it when I wouldn't recommend it to anyone.

I think it's a much different learning curve than with any other technology. I'm plenty adept at learning new things, but this was just unnecessary complex, with nothing to redeem it.

[csytan]

I'd have to agree that Django on appengine is a big pita for the reasons you mentioned. Django is a large framework, and was simply not designed with interchangeable backends in mind. Getting it to work either requires a lot of black magic monkey-patching or foregoing the majority of built in features.

On the other hand, I have found the datastore api (and most of the other apis) to be well designed. It works very well with lighter frameworks such as tornado.

[tommynazareth]

It sounds like your problem with App Engine is that you're Django. Yeah, Django is not built for the App Engine data store, so why not use something that is? I've used the Tipfy and Flask frameworks (both are a thin layer on top of Werkzeug), and they experience has been great.

[astrofinch]

I haven't tried djangoappengine, but it seems possible it would abstract away most of the datastore-related stuff and make the admin work.

[endlessvoid94]

Not true, unfortunately. For example, creating objects and deleting them uses a different method (put instead of save). There are tiny syntax differences, also.

Not to mention the fact that designing an information schema for a SQL database is quite different from designing an info schema for a hash-table like datastore (which appengine has).