With the pip-tools package and pip-compile, having a stable requirements system is pretty straightforward. We have no problems with pyenv and pip locally, and d

With the pip-tools package and pip-compile, having a stable requirements system is pretty straightforward. We have no problems with pyenv and pip locally, and dh-virtualenv in production. We're considering moving to poetry as it brings a load of nice features and more automation, but really it's not been a problem for us. Node I'd say is about as complicated. You still need to care about the Node version, about as much as the Python version. a node_modules directory is pretty similar to a virtualenv, it's not portable, maybe a little more reproducible by default, but no better than a pip-tools managed requirements file in my experience. Package upgrades are a little trickier than with pip-tools. You still need to care about things like what version of OpenSSL is on your machine, or do you have libpq installed, etc. One problem with JS is whether to compile and if so, how, what do you run, etc. You probably don't want to ship a node_modules to production with all the random package build scripts that it includes, so there's some additional complexity there introducing a build process.