Ask HN: Do you know useful courses/certificates to reach Staff Engineer level?

Currently, I'm the engineering manager of a small team of 5 engineers, including myself, at a startup. I have a good idea for almost all of them, but I'm looking for advice about what external training can be helpful for a staff engineer track. However, I've issues finding practical courses and certifications.

I'm not looking for specific training but more general knowledge, like AWS Solutions Architect certification. This certification was helpful for me in the past, but we are heavy GCP users, so I'm opening the scope to find good content.

Thank you!