> senior engineers have always been required to sign off on changes from junior engineers.

definitely a team by team question. if it was required it would be a crux rule that the code review isnt approved without an l6 approver.

It’s part of the change management process that all code is reviewed. This is needed as per several different compliance agreements. What’s probably happened is poor peer reviews from other junior engineers gets missed. That’s a lot of code reviews to send upstream.