The engineering manager was right. SQL is the most pervasive programming language in existence. It doesn't get that way because nobody uses it. Maybe you don't use it much, but unless your consultancy specializes in some tiny niche where SQL isn't actually needed, you might want to rethink that. I've seen far too many projects where developers looked down on SQL as some sort of not-so-necessary evil, and they've all ended up reinventing it. Extremely poorly.