Deployment of multiple functions

The tooling for deploying a single FaaS function is very robust at the moment. However, the tooling required to deploy multiple functions at the same time or co-ordination of deploying multiple functions is lacking. 

Consider a case where you have multiple functions that make a serverless application and you need to deploy all of them at once. There are not many tools out there that can do that for you. The tooling to ensure zero downtime for serverless applications is not robust enough yet. 

There are open source solutions, such as Serverless Framework, that are helping to solve some of these issues, but they can only be done with support from the cloud provider. AWS built the AWS Serverless Application model to address some of these concerns, which I will talk about in later chapters.