Random voice here: they should get better at SQL. Not 9 joins and GROUP BY and HAVING and other magic. But two joins and GROUP for sure. If one gets the 3NF already then join and others are a quick (2 week) learn.

I'd pick that before traveling the DuckDB path.

It’s not a good database for many storage workloads because it only allows a single process to write to it. For example you wouldn’t want 20 app servers writing their logs or metrics or traces to a single duck db instance. You would instead have them write rotating log files that are somehow aggregated then queried through duck db via something like grafana.

So the operational savings are more for using it as a light weight data science tool that excels in specific workloads like geospacial. Wherever you need to do those computations more locally it will excel.

I don’t really think sql is a mandated devops skill, though a basic understanding of databases certainly is. Between online content, LLMs, as long as you can iteratively improve a query part by part through explain analyze etc it’ll be sufficient.

Since when is strong SQL knowledge not a core skill for developers? I suppose it's the rise of frontend vs backend specialization that is the cause?

There's no point in learning any much deeper SQL anymore, AI assistants have largely solved SQL querying. Just ask for what you want with natural language.