They ask you to be there early just to be sure, but you don't have to, it's at your own risks.
I've done 30 mins at smaller European airports no problems. Online check-in, only carry-on luggage, 10 minutes for security and you board among the lasts with minutes to spare. Of course you don't have a lot of margins if anything goes wrong, but at airports you know it's definitely doable.
Where? I was flying in Europe and was asked to be on airport 150 minutes before departure.