After I applied for the position, I've got an email from company president for phone interview next day.
I've been asked many questions about my current and previous role such as troubleshooting, maintaining Linux environment, etc, then I've been invited for on site interview.
On site interview started on time with company president and I've met with one technical person to make sure I could be compatible with him in that position. Overall interview took one and a half hour, then president said,I'm hired but he doesn't know the budget of this position, went over his emails and he told me the salary range for it, in addition he mentioned that I would see it anyway when I get the offer.
I've followed up via email next day, asked when would I get the offer, same day I got a reply that I should get an offer before week ends however I never got any offer from them.
Unfortunately, this is kind of rude once the president of the company says you're hired then there is no offer. Please consider my experience when you interview with that company.