GCE provides Virtual Machines for businesses to host their data. These Virtual Machines house the instances that actually serve data to the users in real-time. Our architecture consultants would pick a specific number of instances for your app. This is done keeping performance and costs in mind.
There are a number of availability zones for GCE where you can pick a VM and get going. Depending on the traffic, your app is expecting, number of instances put into use may vary. For a basic app startup, we do not go beyond a couple of instances and SQL databases. However, if you expect a large number of users that is more than ten thousand, we may throw in additional instances, load balancers, CDNs etc.
If you run websites or app that receives traffic spikes in holidays or some particular time of the day, then a lot of other services can be put into use in your architecture. GCE has a lot of products and services for Big Data and Machine Learning that is great for technology companies wanting to make a mark in this direction.