The honest framing: both are fine, they pull toward different futures
Node.js is JavaScript on the server, one language across the whole stack, event-driven, superb at I/O-heavy work (APIs, real-time features, high-connection services). Python is the data language, unmatched libraries for AI/ML, data processing, and scientific work, with perfectly good web frameworks (Django, Flask, FastAPI). The syntax war is noise; the gravity is the decision.
Node wins when
The product is a web app with lots of concurrent connections (chat, live dashboards, APIs serving a JavaScript front-end), one language across front and back reduces your team cost, or the Node hiring pool in your region is deep. Node + TypeScript at scale is a proven, boring-in-a-good-way choice.
Python wins when
The roadmap includes AI features (LLMs, RAG, fine-tuning, the entire tooling universe speaks Python first), data processing is core, or the team is analytics-adjacent. Python backends serve web fine, the GIL's concurrency story is a 2026 footnote now, the argument is ecosystem gravity, not capability.
What it costs you later
Choosing Node then adding serious AI → a Python sidecar service appears (two runtimes to operate). Choosing Python then needing real-time scale → architecture gymnastics around the event loop (or a Node sidecar). Both sidecars are normal and fine, just budget for the second runtime, whichever it is.
The tiebreaker questions
Will this product touch AI/data within 18 months? Is the front-end JavaScript-heavy (shared language savings)? Who is already on the team? Three answers, one clear lean. If the AI question is "yes", that lean is usually Python or Node-plus-Python-sidecar, say the three answers out loud to a human and the choice makes itself.