My first experience with agile was not with Scrum but XP, and it was a very good one. There are so many people here conflating Agile with Scrum, and I shouldn’t be surprised I guess, but my goal was not to invoke the “No true Scotsman fallacy”, I don’t care about pointing who is agile and who is not, or what names you use for what, but I do care about the principles behind it, they can give us very good ideas on how to balance certainty vs uncertainty, upfront design vs feedback cycles, in whatever environment you are. Some environments you will need to balance more to one side, some more to the other.