Managers should absolutely be very well versed with arch and design. Rather, they should review and share their feedback on all design docs. On code, I would say that it depends on size of team etc. But they shouldn’t shy away from getting their hands dirty when the situation demands. This requires they they stay close to the system from an engineering standpoint.
Managers role shouldn’t just be people management. Technical responsibilities should be a big part of it and they should be involved in ensuring they are designed inline with the future scalability requirements.
Thank you for reading Leonardo and raising this crucial point.