Maybe it's just the positions I've ended up in, but my DE roles have required a TON of ops as well. You can build all these pipelines, but you will be absolutely buried in operational work if you can't get the automation squared away. With the role I've been in for the last 2 years, the most significant things we've done were done in Terraform, Ansible, and Prometheus. Sure, there's lots of SQL and Python, some Java, some Scala, but the biggest issue has been getting the system to where we get useful and actionable alerts and downstream data consumers get notified about late or missing data without requiring manual intervention from the data engineers.