Ask HN: Node or Python back end?

I'm starting a project and my team is debating what type of backend to use. The question is what kind of environment: python/flask or node/js? It's a CMS that will incorporate machine learning in the future. Front end is in React, postgres database.

Ultimately we’re seeking a decoupled and flexible architecture. This is one of the first technical projects I’m in a quasi-leader on and I want to make a well reasoned decision.

After research, ultimately either will work. We don’t anticipate scaling beyond 10k users for the first few years, so huge loads aren’t such a problem. Pros and cons as I see them:

NODE - PRO: That’s what I know and can work faster in node. Getting a working product asap would provide a huge benefit at the beginning of the project. - PRO: I know senior folks who can contract in that environment, so I could get help from great engineers. - CON: Node can be complicated. The environment will have to interact with machine learning which will most likely necessitate additional complexity.

PYTHON - PRO: There's a senior person on my team that know's python better, though their primary role in the company isn't as a developer. They'd be available to consult on engineering issues, but it would be difficult for them to lend their expertise in Node. - PRO: Potentially easier integrations with machine learning. - CON: I don’t know python, so there’s going to be additional ramp up time to a functional product. There might also be additional problems I don’t foresee because I don’t have experience here. I don’t mind learning a new language, it’ll just be slower/wonkier at the beginning.

I’m maybe being a bit vague, but after research I'm landing somewhere in the middle and these are the thoughts I’m weighing. Do you have any insights that would tip the scales drastically? What would you do?