Ask HN: Sample Code for Common Scenarios?

While developing software we encounter common scenarios like querying a DB, getting data from an external API, posting some data to an API, etc.

I want to know if there is a place where all these common scenarios are implemented using best practices so that we can just use that framework and simply modify it to suit our needs?

Searching google we usually get the answer from stack overflow but that is generally not best practice answer, its more like code snippet.

For example, I want to create a project where I need to query data from an API and manipulate the data and then use it in some form. I was looking for the best code structure for this scenario (how should I structure my classes to achieve this)

Searched google and github a lot, but there is no such repository of common scenarios implemented for others to modify according to their needs.

thanks for reading! Will be grateful if someone can help.