he means that he's using stuff like Lambda, Cognito and other PaaS services provided by Azure and AWS - not considering the cloud as IaaS only providers.
The problem of “lock-in” is overblown. You’re either going to be locked in to your infrastructure choices or spend more money on both resources, maintenance and personnel trying to avoid lock in and you’re going to have a suboptimal solution that doesn’t take advantage of all the provider offers.
Even if you try to avoid lock-in. It’s usually not worth the risk of regressions and downtime to change your underlying infrastructure once you build on top of it.
The chances of AWS or Azure going out of business in the grand scheme of things is not worth the trade off.
I was faced with the same problem recently, and the imagined glory of being able to switch my entire stack from AWS to GCP (or Azure) with a config flag made me realize two things:
1. Being able to do this would mean lots of work to abstract and polyfill the discrepancies between providers.
2. If AWS or Azure goes down globally, everyone else would be too busy freaking out about their own problems than be worried about the downtime of your SaaS.
