How do I get hired at a startup as an older person?

As a founder, I would absolutely not be against hiring somebody older.

You have not stated how old you are but I would assume you're in your 40s/50s.

The most important thing is that you have cutting edge knowledge and are flexible in how you're gonna approach things and solve problems.

The reason founders like to hire young employees is not because they are young and can therefore work at the company much longer before they retire.

It's because - usually - they are easier to train, more eager to learn new things and just more "malleable".

So if you can somehow prove that you have as much (and maybe even more) 'current' knowledge, don't have a fixed mindset, can draw from your experience but not live and die by how you have done things the last few decades, you'll be fine.

I'd hire you then.

Sell your age as an asset - not as a disadvantage to be hidden.

And for the position you want (sales, not development), it actually is an advantage. Also investors might like the idea that there is not only a bunch of students in the startup, but also someone who gives the whole venture a bit of stability.

Based on how old the startup is, the answer would change drastically.

It comes down to the flexibility and the price. It seems to me that you are looking for a place that is bleeding edge, likely prerevenue and potentially even still bootstrapping. In that case, you would earn your stripes by doing your job as if you were founding the company yourself. Be prepared to get paid down to, and including nothing. Equity is still worthless at this point as well, which is why you need to take that approach. Doing your best work here will turn your equity into something valuable and worthwhile.

The process is self-culling, so if you find this isn't working for you, think about what you are really looking for.