> When looking at the cloud resources, we noticed many On-Demand EC2 instances with relatively low CPU utilization, which can be expected considering they don't have customers yet. As a software consultant myself, I'd probably stop the conversation right there and ask why they are building such a robust distributed system — SQS, SNS, etc — without any customers. Still want to be deployed in AWS? Toss the damn app on…
A single EC2 instance is an equally bad trade-off on the opposite side of the spectrum from over architected SQS, SNS, etc… The ideal trade off is a single Kubernetes cluster with as much in the cluster as makes sense for the team and stage of the project. As you say, toss the app on a single node to start, but the control plane is tremendously valuable from on the onset of most projects.
A startup that outgrows an EC2 server will be making enough money to hire more people to scale the system properly than what was initially designed: trading away everything for development velocity.
Kubernetes is not the right tool for this startup. Kubernetes is what large, old-school non-tech companies use to orchestrate resources, because it’s easier to find someone that “knows k8s” (no one knows k8s unless they’re consulting) than it is to find someone that can build properly distributed systems (in the eyes of whoever is in charge of hiring).