People throw around "vendor lock-in" like it's a binary — you either have it or you don't. That framing is why the conversation usually goes nowhere. Lock-in isn't one thing. It's four different things stacked on top of each other, each with a wildly different cost to unwind, and once you separate them you can actually decide what's worth worrying about.
The four layers
Data. Proprietary formats, and — the real killer — egress fees to get it back out. Cheap to design around early, brutally expensive to fix late.
Platform. The vendor-specific managed stuff: serverless, managed databases, IAM, observability. This is where the deep lock-in lives, because these services are genuinely good and have no clean equivalent next door.
Contract. Renewal clauses, termination terms, committed-spend discounts that quietly jack up your switching cost while feeling like a deal.
