Danger signs you are partnering with a dreamer?

Dreamer by itself is not a bad thing but I presume you mean someone who is JUST a dreamer but doesn't seem like someone who would actually do the work to achieve those dreams ?

The best indication is their past actions. What have they done so far that gives you any indication they are worth partnering with. If nothing, I would definitely think twice.

Business is extremely hard. You need to partner with people who ideally have all of the below:

1. Perseverance. They understand that good things take time and need to constantly fight against odds to achieve success.

2. Dedication and focus. They are not all over the place. They only want to do this.

3. Relevant Skills/experience. You could be a first time business founder/partner BUT what skills do you bring to the table that are relevant in some ways to this partnership ?

Dreamer is

- typically speaks more and either not listening or ignoring what you (or others) say.

- typically excited about [mostly] his ideas and either refusing or not participating in discussions about the next practical steps.

I know of a perfect dreamer which i never enter into mutual business with. However i often listen to his ideas.

I think you have to define dreamer.

I think the very premise of a startup is based on an idea of a dreamer. Otherwise the idea that give the startup a competitive advantage would have been taken already. The dream just has to be achievable and rooted in reality.

So maybe you are talking about someone who isn't rational, isn't reasonable, or are rigidly idealist (and not matching your/company ideals). Any signs of these qualities would be a warning. Stuff like the person not supporting their opinions with facts and insisting they are right could be a warning sign. Emotionally based opinions, business actions, or outbursts that are detrimental to the startup could be another.

I haven't encountered this description of an off-base "idealist" founder, however during my time in SF I met many people like this.

Even those with impressive credentials, they seemed to jump from buzzword to buzzword starting something new every 6-8 months but never really committing or finding success.

Generally, I always avoid non-technical founders or first-time founders. Businesspeople who only have corporate experience and decide they want to "hire an engineer on the side" are should also be added to the "dreamer" definition IMO.