I read an article from Medium Titled "The Evolution of Container Usage at Netflix" and watched a couple of videos on the topic, but it is unclear to me why Titus (referenced in these) should be used. Is it different than Kubernetes or should it be used in concert with Kubernetes?
It's different to Kubernetes in that it seeks to leverage existing AWS services instead of bolting on top. Kubernetes supports a number of cloud providers and contains a number of components that exist in AWS already.
Although we're starting to see better kubernetes AWS integration and with AWS joining the cloud native foundation this is only going to get stronger.
Titus seems to be an alternative to Kubernetes but its not available yet. My bet is AWS will strive to better integrate K8 and likely Titus won't take off even when it is released.