Quoting from the article: "This accomplishment would not have been possible for our three-person team of engineers to achieve without the tools and abstractions provided by Google and App Engine."

Talking about the use case from the article, they release the puzzle at 10 and need to have infra ready to serve up all the requests. On AWS, you need to pre warm load balancers, increase the quota of your Dynamo DB, scale up instances so that they can withstand the wall of traffic, ... and then scale down after the traffic. All this takes time, people and money. Adding few other things author mentioned: Monitoring/Alerting, Local Development, Combined Access and App Logging ... will take focus from developing great apps to building out the infrastructure for apps.