I wasn't 35 and I didn't have kids when I joined my current startup, but I am and I do now. I'd have to say a startup that is looking for my skillset would be very foolish to pass on me for a 25-year-old who worked 80 hours at half the price. That sort of focus on cost and hours rather than value delivered and mistakes avoided will drive a startup straight into the ground.

Exactly. That's the problem I've noticed: Do you really want to hire someone who takes 80 hours to accomplish something that takes 8 hours for someone else? I think we've all seen this happening. I was brought in to a parallel team one day because they were about to miss a deadline. Turns out 25 year old guy was trying to build a graph database from scratch. He didn't know that he was building a graph database, and wasn't really aware they existed. He just knew what he needed, and went about building it. He spent a huge amount of time building his own awful, non-performant implementation. I told the team lead to get Bob to help. Bob has kids who are in their mid 30's. Bob sat down, logged into the VM, and a few hours later had an instance of Neo4J running and hooked into the app.

But hey, he thinks foosball tables don't belong in offices, so why hire him at a startup?

Please don't down vote him for highlighting the current situation.

The question wasn't "should startup hire..."

And he answered with what's happening in the field, like it or not.

How does one down vote posts here?

Of course there are laws against some of those things, with (probably) exemptions if there are fewer than X employees. One place told me "we are not hiring employees now, but we can just give you $yyy/mo."

I would straight forward look for skillsets and productivity(productivity includes guys availability i.e. whatever is needed) and attitude rather than age, Period.

I've worked solely at startups my entire career, from 20 to 50+. Not been an issue anywhere.