'Founding' technical roles are a signal to not join a business

There are two things that are generally true about open technical roles that are advertised with the word "Founding" in the title (e.g. "Founding Engineer" or "Founding Data Scientist"):

1. They will likely pay less than the market rate for the role
2. They will give you nothing like the equity associated with any reasonable definition of the word "Founder"

In the best case the advertisers are using the word "Founding" to indicate how early they are on their journey, and that you (as the person applying) should understand all the positive (but mostly negative) connotations that has. This extends to point (1), as the advertsier is seeking to attach some kind of amorphous "title compenstation" to a role that is otherwise uncompetitive. You only add "Founding" to a job title if you need to and the need is rarely to the benefit of the person taking the role.

In the worst case, it's a cynical attempt to hire someone to do a lot more than would be expected for someone taking the role sans "Founding" prefix, without compensating them for it. Join us as an engineer but you'll get the opportunity to do so much more (but please don't ask for more salary or equity, thx).

Post-hoc "founding" titles

Having "Founding Data Engineer @ Open AI" has a non-zero value on a resume, compared to "Data Engineer @ Open AI". However, this value is conferred by the reputation of the company, that reputation needs to be earned for it to have value. People trying to hire these "founding" technical roles belive that additional value is conferred automatically. That the mere existance of their business and someone's early particiaption in it confers that same value. Sadly, it does not.

Never be afraid to take the title in a business you've been an early member of, but never let an early business convince you a "founding" title confers material value before you take a job.