One of the hardest things about having a system up and running is administering and maintaining our own clusters. Although serverless is a paradigm aimed at solving this problem entirely, in reality, there are some situations where we still need to provision and take care of servers by ourselves.
The idea behind serverless and Docker is to have a balance between reducing cluster maintenance and administration, and having full control of the cluster. Using Docker is a great way to help balance this.
Along with this balance, the most attractive driving factor for serverless is the price model. However, we have found that using Docker on EC2 Spot instances, given the competitive price, is sometimes even cheaper than AWS Lambda or other cloud functions. So with Spot instances, we will get the cheaper price, while our functions will not hit any limitation...