[mjb]

> For example, the reliance on external infrastructure could lead to vendor lock-in, making it difficult to switch providers or move back to an in-house solution if needed.

Lambda's runtime API is quite simple, and well documented (https://docs.aws.amazon.com/lambda/latest/dg/runtimes-api.ht...). Other than that, Lambda functions are "just" containers running on open source runtimes (named versions of nodeJS, Corretto, etc). Local implementations are also available.

Clearly, the operational properties (like reliability and scalability) that these folks point out are difficult to achieve on-prem.

> Additionally, there might be concerns about data privacy and security when dealing with sensitive information in a cloud-based environment.

Lambda's approach to security is documented here: https://docs.aws.amazon.com/whitepapers/latest/security-over... for the compute components, and we discuss some of the "why" behind that in the Firecracker paper (https://www.usenix.org/conference/nsdi20/presentation/agache).