The failure modes are quite different in my opinion. While they each offer similar services and management techniques/interfaces, where an expert in AWS differ

The failure modes are quite different in my opinion. While they each offer similar services and management techniques/interfaces, where an expert in AWS differ from you is when things go wrong. I'd absolutely want a person who knows AWS to handle a production failure across multiple regions and available zones - no offense to your knowledge base, but a person knowing how to recover from GCP errors is going to be out of their comfort zones in building / recovering from massive AWS failures. It's like backups - only in the recovery do you know whether your initial backup worked. I wouldn't want to find out after the fact that an engineer I hired who had GCP experience didn't know how to design a system to recover from a catastrophic AWS error. And these days, the cloud is just another person's computer, so errors and failures are going to happen - best be prepared. Best way you can prepare yourself is to get some AWS experience! Spend a bit of money or use educational credits to build yourself mini clusters, and just see how to fail them, and how to interact with the management plane during an AWS outage (it's not hard to find an AWS outage - it happens on US East every few months or so).