There ware few drawbacks I had to face against my job interview. klingt das natürlich?

I'm not sure about how you're using "drawbacks." A drawback is when something is mostly good, but there's something about it that's bad (the drawback). For example, "My new job is almost perfect, the only drawback is that the commute takes three hours." It isn't a drawback because it's unpleasant, it's a drawback because it's the unpleasant price you pay for something pleasant.

So for a job interview to have drawbacks, it's usually some price you have to pay that you know in advance. Like, "The drawbacks of doing the IBM interview are that I'll miss my kid's dance recital, and if my current boss finds out I interviewed there I'll be fired." Usually you'd be talking about the drawbacks of the job itself (salary, location, hours, not liking the boss) rather than the interview.

If you just mean that things went wrong or were difficult, you might say, "There were several things working against me at my job interview," (meaning there were reasons for it to not go well, like being late or not having enough experience). Good words for that instead of "drawbacks" would be "problems," or "issues."

Another thing to watch out for is the difference between "few" and "a few." "A few" means several, but "few" means "not many."

"There were a few rats" = there were several rats.

"There were few rats," = there were not many rats.

They both mean "a small number," but the mood is different. Therefore:

"There are a few strong men." = "There are several strong men."

"There are few strong men." = "Almost no men are strong."

And:

"There were a few problems at my job interview." = "My job interview had some problems."

"There were few problems at my job interview." = "My job interview was almost perfect." But this sounds weirdly archaic, almost no one talks this way anymore--or, you could say, few talk this way still. ;)

You almost always use "a few" in modern English rather than "few" alone.