When I started doing software development there was no ‘stack’. In the old days of DOS you were either writing in BASIC or C and simply read and writing data to files using your own format.
Then 4GLs came along (like dBASE and FoxPro) and suddenly you could read and write data much easier and use SQL to extract data.
I am currently using Python (3.7) and MS SQL Server on a VPS (running on Linux). I have been using Microsoft SQL Server in my day job for years (decades in fact). So Python grabs data from the Betfair API and in-play tool uses betsAPI. I then store the data in MSSQL.
I also use Python for extracting data from CSV files at football-data.co.uk which I was using for score predictions. Currently not using this as the poisson method wasn’t proving reliable enough.