@kaia Yes, Go is awesome. It is really easy to learn and pretty performant. At least more performant than JS or Python.
I don't push to CSV. I have a xlsx file that the customer provided. There is a library (https://pkg.go.dev/github.com/xuri/excelize/v2) I use to read the data from the file and write it into a PostgreSQL database. Of course this data needs to be normalised beforehand.
When that is done I can write a server that returns the data and filters it according to the users input.