Ive seen a few ads today for baristas (Im currently unemployed) and none of them asked for certification.
They all asked for experience.
Having said that, I believe passion is a key to getting your foot in the door.
About 3 years ago now I was in the same position and managed to talk myself into a barista position with zero experience.
He wanted nothing more to do with me after I said I had no experience in a cafe.
Mind you, I was armed with my certificate and pictures of my home equipment and dared him into letting me show him I could handle his machine.
Long story short I got the job.
Now back to those online ads...if they advertise for experience I dont think youll get a look in.
I think youd need to approach them face to face like I did.
Some of the ads mention the establishment so its possible to bypass an online application.