December 10, 2025
Speed vs Packages: The Python Roast
Python Workers redux: fast cold starts, packages, and a uv-first workflow
Python goes global and fast — crowd cheers, then panics over missing packages
TLDR: Cloudflare’s Python Workers promise faster cold starts and easy packages via Pyodide. Commenters point out missing big-name libraries, ask for AWS SnapStart benchmarks, and flag snapshot quirks like “no randomness at startup,” leaving excitement mixed with caution.
Cloudflare just vowed to make Python go worldwide in a snap — super-fast starts, easy packages, free tier — and the internet clapped… for about five minutes. The launch promises “2.4x faster than Lambda” and “3x faster than Cloud Run,” plus one-command deploys and a Python-native workflow. But then commenter jtbaker drops a bomb: Pyodide’s latest “BREAKING CHANGE” removed big-name libraries like polars, pyarrow, duckdb, and geopandas (receipts here). Cue the collective: “So what can we actually install?” The vibes turn from speed flex to package panic.
Benchmarks? jeff17robbins calls foul, noting the AWS feature “SnapStart for Python” wasn’t included. The crowd wants apples-to-apples timing, not cherry-picked victory laps. Meanwhile, BiteCode_dev questions whether anyone’s using this for serious work, calling it more “quick script” than production muscle. Then pedrozieg drops the nerdiest twist: to make those cold starts fast, Workers snapshot your app at deploy and effectively forbid random numbers (PRNG) during that phase, reseeding later. Translation: some “do stuff at import” habits may bite you.
The memes write themselves: “Deploy to region: Earth, but not to polars,” “Fast starts for apps that don’t start,” and the classic one-word review: nice. The community’s verdict? Excited, skeptical, and loudly demanding real-world demos plus a package story that doesn’t end in heartbreak.
Key Points
- •Cloudflare’s Python Workers now support any Pyodide-compatible package, expanding beyond a limited built-in set.
- •Dedicated memory snapshots cut cold start times; tests show Workers start 2.4x faster than AWS Lambda and 3x faster than Google Cloud Run using common packages.
- •A uv-first workflow streamlines package installation, and example deployment uses workers-py and pywrangler.
- •A FastAPI app can be deployed globally in under two minutes across Cloudflare’s edge (330 locations in 125 countries).
- •Platform features include HTTP handling, outbound requests, cron triggers, Workflows for Python Workers, Durable Objects for WebSockets, and a free tier (100k requests/day, 10ms CPU per invocation).