We're using app engine for www.jukaroo.com. We've been using it for a year now and after a lot of invested time are migrating away. The number one reason to use

We're using app engine for www.jukaroo.com. We've been using it for a year now and after a lot of invested time are migrating away. The number one reason to use it is the one click deploys but we've found that time saved there is lost working around app engine's quirks. The service is buggy (set a page to refresh every ten seconds or so and watch how many random 500's it will throw - there's a monkey patch floating around for the random datastore timeouts that are partly to blame). It's also slow compared to other setups I've used (currently running vanilla django at webfaction). The limitations are many and absolute (dig around but off the top of my head no threading, no long running threads, no push, no naked domains, no python c libs, no ssh no advanced image processing, no support, no support and no support). Core apis I've had to patch: imaging (black lines on edges of pics), datastore (random timeout errors), inbound mail (improper body and attachment handling) and probably others that I've forgotten about. There is also no portability at this point. I've seen one project that will run an app engine app on ec2 but I haven't used it. I think it's a cool project but if you want the unhindered ability to build really good products I can't recommend it. Also don't mistake app engine for a hosting company. The experience for us has been 'you are lucky to be using our nifty cloud' and not 'thanks for your business, we're here to help'.