The takeaway here isn’t that serverless doesn’t work, it’s that the authors didn’t understand what they were building on. Putting a latency-critical API on a stateless edge runtime was a rookie mistake, and the pain they describe was entirely predictable.
Most cloud pain people experience is from a misunderstanding / abuse of solutions architecture and could have been avoided with a more thoughtful design. It tends to be a people problem, not a tool problem.
However, in my experience cloud vendors sell the snot out of their offerings, and the documentation is closer to marketing than truthful technical documentation. Their products’ genuine performance is a closely guarded proprietary secret, and the only way to find out… e.g. whether Lambdas are fast enough for your use case, or whether AWS RDS cross-region replication is good enough for you… is to run your own performance testing.
I’ve been burned enough times by AWS making it difficult to figure out exactly how performant their services are, and I’ve learned to test everything myself for the workloads I’ll be running.