For a startup, though, if it succeeds, you have to assume that a good portion of the code will eventually be refactored at some point, or retired as the buisine

For a startup, though, if it succeeds, you have to assume that a good portion of the code will eventually be refactored at some point, or retired as the buisiness is flushed out. I have a feeling we'll also see some projects for transferring Lambdas between IaaS providers, including on-Prem at some point. I'd be more concerned about lockin at the DB-level but even that could be accounted for with up-front decisions to not use Dynamo, etc. if you were really concerned.