Node.js on Google App Engine Goes Beta
Don't use AppEngine.  I migrated Homejoy off of AppEngine in 2014 and I can't recommend the platform for any reason whatsoever.  It's slow, expensive, not based on OSS, and not particularly stable.  Bits of it (urlfetch, search, etc) would go down for hours at a time and you're basically hosed until they fix it.I think Heroku is usable with a similar level of effort -- and you have a much easier migration path to something else if you're not using Google's proprietary datastore IMO.