Hello all,
I have applied both last year and this year to attend DevDay, both times sadly missed the mark, was wondering if anyone knows what (if any) are the requirements in order to be invited.
Thank you for any help 
Hi and welcome!
I’d image it’s a combination of demand, luck, and the persuasiveness of your application.
I’d imagine San Francisco is probably the most popular location by a large margin, so competition will be fierce. All applications are reviewed by a real person too, so being thorough in explaining your experience and why you should attend should help a lot.
Apart from those two, probably just a bit of luck. I wish you luck for next year!