I checked any additional features on Qlik Sense Help but could not find any.
So I will try to explain what we do in QlikView so it should apply on Sense as well.
- After ETL finishes, insert a record on a table on ETL-side indicating completion of ETL times.
- Create a Sense app and read that table. Check if ETL finished on time today (regarding on your condition such as Today()) etc.
- Make the app fail if timestamp of ETL completion is old and make it success if it is right or vice versa. This app just checks the ETL time(ETL_check.qvf). Define a task to it.
- Define a task to your main app (main_app.qvf) such a trigger on completion of ETL_check.qvf.
Hope it's clear.