Here are some links related to my talk at JFokus 2022 in Stockholm:

Potential data sources:

fivethirtyeight (data from sports, politics etc)
github.com/buzzfeednews
kaggle.com/datasets
opendata.socrata.com
github.com/awesomedata
cloud.google.com/bigquery/public-data
UCI Machine learning Repository
www.quandl.com/search
www.data.gov
www.academictorrents.com
aws.amazon.com/datasets
Open Data Germany
https://github.com/public-apis/public-apis

Slides and video

Slides and video will be available via JFokus (in a couple of weeks)