Ask HN: What are the best multi-day/track software conferences these days?

I just have come back from a two days conference with a decent program. It was about Javascript, APIs, ML. and although I was familiar with most of the stuff, I wanted to spot new trends, new technologies, etc.

But it was actually pretty disappointing. It was not a cheap conference at all. But I found a lot of bluff. A lot of twitter-"prima donna"-speakers talking more about themselves than the technologies, motivational talks ( I appreciate the value of motivational talks, but they were out of context as the conference was rather targeted to enterprise folks who could spend the money on it ), promotional talks ( i.e. the typical brands selling their clouds ), and very few stands...

Maybe I should have spent more time researching but this was a 1st event and the organisers are seasoned (devoxxx or NFJS like ). But I ended up with the feeling that the moneys could have been invested in something better.

So, I wanted to ask this community. What are the tech conferences that give the best value for money these days?

Edit: Changed the title. To be clear, because otherwise the scope would be too broad, I'm interested about software conferences spanning multiple days or multiple tracks. Not regular meetups, or hackahons or single day small events. Thanks!