Comment by farhaven

If you're looking for a similar event, you might want to check out GPN - Gulaschprogrammiernacht (https://gulas.ch).

It skews a bit more German, but it's essentially a smaller "summer congress" that used to have free attendance until this year (tickets now cost 10€ to cover the breakfast, IIRC). A lot less people there, but the general vibe is very similar.