I don't see an actual question. What exactly are you asking? Personally, I would set up an email filter that helps me ignore their communication (except from the hiring manager) but saves if for later.

@Roland The implicit question is "How do I deal with this situation?"

With my small experience with one startup, this behaviour is unsurprising for me.

Personally, I'd set aside 1 hour to try to get some of the lower hanging fruit tasks done. At the end of the hour, completely disconnect. At least you tried, now relax

While it may be bothersome, you might want to view it this way: They're so eager for you to come onboard, they can't wait for you to actually show up.

One of the key differences between startups and mature companies is the relative lack of work-life delineation in the former. I've been through this, on both sides. Startups founders typically bind very closely, and expect this from new teammates.

I think a lot of folks here are missing or ignoring the fact that they are doing all this to someone who has not started and they are not paying. IMO, it would be a mistake to get involved with what is at best an incredibly disorganized and disrespectful environment, and at worst a cult.

@LamarLatrell - I find that the problem with this is that these days, established corporations are still calling themselves startups.

@Davor agree, zero apparent pathway to becoming no longer a start-up. People basically working their arses off to make people 2 steps higher up the 'horizontal' org chart millionaires. At least, that's the idea. 😆

Is it possible they're sending you messages in advance (i.e. just to have dealt with it on their side) but don't expect you to start reading / dealing with them until you start? If not, I would consider it a bit of a red (or at least yellow) flag... Unless of course, they have misunderstood what you mean by your "start date", and they are already paying you, or there has been miscommunication between the managers there regarding your start date.

...but if they really expect you to be working already, then you can likely expect this during holidays / after hours / possibly weekends as well.

"now they are following up and asking when was my last day at my previous job" - have you clarified to them that, as previously agreed, you are not starting with their company for another 10 days? After that, your last day at your previous job doesn't really matter. You could be holidaying in Antarctica for all they know...

It's worth remembering that 999 out of 1000 startups completely fail. Why do you want to work there anyway?

"I have already compromised on salary and work style for this opportunity" Why?

"now they are following up and asking when was my last day at my previous job" - I almost wondered if they think you are 'overemployed', double dipping or whatever you want to call it.