It's for when you want the benefits of serverless computing for your engineers, but your organization is too big (too many requests) for lambda to be financially feasible. Or you project things getting to that point and don't want to be locked into the AWS ecosystem.

Vendor Lock-in

I was talking to a financial company about aws lambda and they wanted control over the underlying containers/VMs that is running the aws lambda, unfortunately AWS lambda doesn't give you that control and 'fission' does

Kubernetes gets you pretty far along the path of not messing with servers (especially if you use GKE). And we think there's other advantages to Functions-as-a-Service on Kubernetes -- it simplifies the dev workflow, improves server utilization, interoperates well with other services on K8s, etc.