We are using the Beta Scheduled query feature of BigQuery. Details: https://cloud.google.com/bigquery/docs/scheduling-queries
We have few ETL scheduled queries running overnight to optimize the aggregation and reduce query cost. It works well and there hasn't been much issues.
The problem arises when the person who scheduled the query using their own credentials leaves the organization. I know we can do "update credential" in such cases.
I read through the document and also gave it some try but couldn't really find if we can use a service account instead of individual accounts to schedule queries.
Service accounts are cleaner and ties up to the rest of the IAM framework and is not dependent on a single user.
So if you have any additional information regarding scheduled queries and service account please share.
Thanks for taking time to read the question and respond to it.
Regards