The interview process was unclear and disorganised. Nature of the meeting were kept as non-official chats. Technical assignment very time consuming (though not difficult) and time spend for is not compensated. Company doesn't seem to have clear idea, as what they are looking for nor for what purpose. After the interview, dead silence from the company, until I reached out for the CEO.

Informal chat about personal history, hobbies and software technologies in general. Three separate interviews; first with CTO, then with another developer and last a sanity check with company CEO. No software test but that might happen to you depending on how sure they are of your skills. Make sure to get all your agreed benefits on paper if you get an offer.