It started with questions about who my parents are ... but the questions were slowly moving into questions about the country (somewhere in the Middle East) of my girlfriend and my opinion about the political situation there... now I consider them as highly unprofessional and unrelated to the job.
Yes, those types of questions are definitely unprofessional and unrelated to your ability to develop software. And while someone in a comment mentioned that "Some countries require to ask about religion. Some jobs can ask about politics", I shall a) assume that this is not the case for the O.P. since those questions would not come as a surprise (unless, I suppose, this happens to be the O.P.'s first and only interview ever), and b) state that allowing for questions about politics only makes sense if that is the nature of the job being interviewed for.
Sure, there are scenarios in which a candidate's religion and/or politics and/or marital status and/or {anything else of a personal nature} might conflict with their ability to actually do the job. But in those situations, they don't need to ask, for example, about religion if the job requires working on Saturday. They can:
- State that the job requires working on Saturdays so that you know it is not a good fit if you can't work on Saturdays, or
- maybe additionally, after stating the requirement, ask if you will be able to meet that requirement (not sure this would work in all places), and/or
- work with you to find a way in which you could help that wouldn't require working on Saturday for you but does not create an unfair situation for everyone else who is working on Saturday.
Ideally, this type of question is really best left to someone in HR and doesn't really need to be "asked" by an interviewer, outside of them possibly stating various aspects of the position.
Also, there is nothing wrong with a company / interviewer trying to figure out if a candidate is a good fit for the "company culture". But again, there are much better ways of going about than invasive, personal questions. They could take you out to lunch along with 1 or more potential team members to have a more relaxed time of socializing. And, of course, this is most likely a large part of why you were talking to the CEO in the first place.
Please know that I was not offended by this kind of questions since I am not religious or actively involved in politics. Besides that I am just a local. ... Since I am the only candidate left, the chance is big that they offer me the fantastic job.
Ok, great that you weren't offended. But a "big chance" that you get an offer is not actually an offer, it's speculation. Only an offer is truly an offer. What if they "cancel" the position, only to open up a new one of very similar description, or if they decide to "keep looking"? If you don't get the offer, will you still not be offended? If you don't get the offer, will you firmly believe that it's only because you weren't qualified after all, and that none of these non-job-related questions had anything to do with their decision?
And what if you do get the offer? Sure, you weren't discriminated against, but what about those that didn't get the job? Was it because you were more qualified, or because you didn't have "objectionable" political and/or religious views? How do you know that other candidates weren't asked questions that were even more inappropriate than what you were asked? You getting the job does not prove that this company is acting professionally / ethically.
The point is that I consider myself as a professional and expect my future colleagues will be the same.
Well, then you need to consider that the only thing that you truly know about this company is that at least one person is definitely unprofessional. You got a good sense of the CEO, but that doesn't prove that the CEO conducts himself/herself professionally all of the time. It could be that the CEO is just better at not being so obvious regarding their prejudices. You also don't know about anyone else in the company. To view this interview as an isolated incident is a bit naive. While it is always possible that it is just this one person, you have no way of knowing that. You only have your experience to go on.
Another answer here states: "No, don't judge a whole company by the actions of one person. Don't even judge the person because it was a brief conversation and you can't read their mind". WRONG. You should judge them on this basis because it's the only basis you have. And, the interviewer is judging you just the same (based on just this conversation since they also can't read your mind). Do you really think that if you made clearly racist remarks (or something that would normally raise red flags) that they would ignore that as "well, maybe he meant something else". No. This is an interview and you are interviewing the company just as much as the company is interviewing you. And an interviewer represents their company, and the CEO should know that. There is a very good reason why it is common to see/hear the disclaimer of: "The views expressed by ___ are their own and in no way represent the views of the company, its employees, or its shareholders" (or something to that effect).
The only concrete data point you have right now about this company is that there is at least one unprofessional thing going on. That the second interviewer was a Sales Manager doesn't mitigate any of the concern here. In fact, it brings up additional concerns of: a) does this sales person lie to customers to get sales, or find ways to not sell to customers with potentially "objectionable" political or religious views, and b) why haven't you been given a technical interview by a developer or at least a development manager who could determine if you were lying or not? Is it because they don't have any truly technical staff and you are to be their dev manager and/or technical lead?
You claim that this will be a "fantastic job", but you don't know that. Keep in mind that the CEO and company are marketing the position (and the company) to candidates just as much as candidates are marketing themselves to potential employers. Both sides have something to offer the other and are making that "something" as attractive as possible to the other. They don't highlight potential problems with the company and/or position any more than you highlight your faults.
Should I reconsider my decision after what happened?
Based on your desire to be professional and work with like-minded people, I would say that if you get the offer, then before accepting it, talk to the CEO and tell them about what happened in order to see how they respond. If they brush off your concerns then perhaps this is not the ideal job you thought it was. If they seem to take it seriously then that is a positive sign, though still not proof of anything, unfortunately.
This is not a situation where there is a definite answer because it is possible that this really is an issue isolated to this one sales manager and that perhaps they leave and everyone else is great and this ends up being the best job ever. All I do know for certain is that a) you have stated that professionalism is very important to you (good for you!), b) you have not had a technical interview, and c) you did have one rather unprofessional interview. It's a gamble in either direction (any job is, really), and while there are positives, I think the negatives outweigh. I think that you should probably keep looking (I mean, it already gave you enough of a bad feeling to post this question here).
P.S. I do understand why others don't mind this particular circumstance that much since it isn't overtly egregious, but I still question whether these same people would be as forgiving if the question ended with, "but I didn't get the offer".