Transitioning from Heroku Mean Stack to GCP/AWS?

The current generation of bogstandard virtual machine instances at the big 3 will launch with fairly up-to-date languages (e.g. Python 3.10, Node 16) which may break whatever you are running.

It's tricky to avoid that. If you know the node version you developed with, I highly suggested pulling a docker image that runs that node version and then pulling your repo in.

Other small prod challenges might be getting SSL working, in practise meaning your backend needs a domain not just an IP (you need it for Chrome to call APIs these days more or less), things like port firewall rules (different for different cloud stacks) and also for the frontend, the nginx/apache request forwarding (depends on SSR/mechanism... older single-entrypoint react apps need to redirect all requests to the / index without ruining the route lok up)

I dealt with the demise of Free Heroku a few months ago, and it was a big deal because I needed these projects online, since I'm early in my career and job searching (great timing, I know). I hosted them on my own linux server at home for a while using PM2 and nginx. Recently I decided to try AWS, mostly so I could add it to my resume. Setting up an EC2 Virtual private server wasn't much different than getting my home server running. Very different than Heroku though.

technical challenge seems manageable, they got complete docs and AWS suppor reps are responsive.

financial challenge is much more of an issue.