You can set global defaults for some keywords. Each default keyword is copied to every job that doesn’t already have it defined. If the job already has a keyword defined, that default is not used.
For example - the correct way to specify a default image is by using the default keyword:
default:
    image: python-latestafter_script
artifacts
before_script
cache
hooks
id_tokens
image
interruptible
retry
services
tags
timeoutdefault:
  artifacts:
    paths:
      - "$LOGFILE"