Measured 2026-10-16 on Docker Desktop 4.54.0 / Engine 29.1.2 (macOS, Darwin 24.6.0)

== start time (base images already pulled)
alpine run: 0.37s / 0.44s / 0.27s      (docker run --rm alpine true)
python run: 0.45s / 0.37s / 0.28s      (docker run --rm python:3.13-slim python -c 'print(1)')

== image sizes (docker image ls)
python:3.13-slim 204MB
alpine:latest 13.6MB

== runtime: host vs image
host:      python3 --version  -> Python 3.14.0
container: python --version   -> Python 3.13.16

== kernel
host: Darwin 24.6.0
kernel seen by: alpine=6.12.54-linuxkit python=6.12.54-linuxkit ubuntu=6.12.54-linuxkit
os-release: alpine=Alpine Linux v3.24 | python=Debian GNU/Linux 13 (trixie) | ubuntu=Ubuntu 24.04.5 LTS

== image vs container (3 containers from alpine, each writes /note.txt)
demo-a sees: hello-from-a | files named note: 1
demo-b sees: hello-from-b | files named note: 1
demo-c sees: hello-from-c | files named note: 1
fresh container from same image: cat: can't open '/note.txt': No such file or directory

== first Dockerfile (3 lines, base cached)
build: 0.5s
hello from Python 3.13.16