I mean, even like J̶e̶n̶k̶i̶n̶s̶ and Kafka were barely a year old in 2012. Hadoop wouldn’t be replaced by Spark for 2 more years. Mesos was in its infancy.
Other companies had similar problems to solve, and they also had to build it themselves for the most part.
Other companies had similar problems to solve, and they also had to build it themselves for the most part.