This was the norm about a decade ago. When I was at Hulu, we built our own analytics platform on top of Hadoop, we almost certainly wouldn't have done that today with the amount of off-the-shelf stuff available.
Even things like protobuf or Avro weren't as broadly adopted (>80%) at the time, many many companies at the time persisted stuff using JSON or other text formats (which in retrospect was very dumb, but it was very normal for a while).
Even things like protobuf or Avro weren't as broadly adopted (>80%) at the time, many many companies at the time persisted stuff using JSON or other text formats (which in retrospect was very dumb, but it was very normal for a while).