I think he was referring to where the article said that one of the advantages of breaking a monolith into any amount of services is that they can store the data

I think he was referring to where the article said that one of the advantages of breaking a monolith into any amount of services is that they can store the data in the location and format that suits their task best, and also be written in different languages. I don't think it matters how you split it - if the team working on one module prefers ruby and the team working on another requires python for any 'serious' work you need programmers who understand both to get the 'big picture' of your codebase now. That one guy who writes all his stuff in PERL can write his plugin that way because it just interacts via API. :O Now how do you debug something?