I'm speaking from experience; since I'm actually using some of those I can tell you that assumption doesn't hold in the real world. It's a myth that programs w

I'm speaking from experience; since I'm actually using some of those I can tell you that assumption doesn't hold in the real world. It's a myth that programs written for interpreted/dynamic/scripting languages are automatically portable, because many nontrivial uses pull in FFI-based or otherwise compiled extensions, so a deployment package does include platform-specific code. I can't speak for Django but this is definitely the case for Rails: a Rails application that's been bundled with its dependencies for deployment in Lambda includes x86-64 binaries. I just checked one of our standard templates, and it has 18 gems using compiled extensions. I'm reasonably sure I'd find similar if I go look through our Node stuff, and in any case, it's a documented concern[1]. The point being, where they don't already have it, such AWS services will likely add platform/arch metadata to their deployment packaging, and users shouldn't assume a seamless transition when the option to switch becomes available. [1] https://aws.amazon.com/blogs/compute/nodejs-packages-in-lambda/ https://aws.amazon.com/blogs/compute/nodejs-packages-in-lamb...