Start with AZ400 and specialize / diversify.
Also consider working within a specific industry is important to you - for example, I've worked with a lot of biotech/medical research companies who almost exclusively seem to use Gcloud and a smattering of AWS. More traditional entities will likely have a hybrid on-prem / Azure approach. I see lots of public sector orgs gravitating towards AWS. Tankies love tencent. And so on....
