Ask HN: Examples of Custom ETL Tasks That You've Written?

Inspired by the answers here (thanks jakobeggar) https://news.ycombinator.com/item?id=19192320

Looking for project/product ideas, and to understand what kind of ETL projects are available for freelancers in this space. Any ETL tasks that you wrote yourself, but feel can be automated? Any tools that you used and like? I found https://panoply.io and https://blendo.co