My 15 year old son is such a jerk right now. Is it just the puberty?

YES! puberty will do that, but hang in there, it goes away eventually...but you need to be patient, and demand respect....

And what have you done to punish him for talking back?

Not met many 15 yr olds that don't act like that. I think the terrible 2's are better than the teen years! Just walk away when he acts out. Ignore bad behavior and praise the good. I might say "that's unacceptable to talk to me like that so come get me when you are ready to speak with me with the respect I show to you". Sometimes they don't realize they have gone nuts. It's like PMS but for boys! Hormones make them act crazy sometimes

My son is 18 now, but 15 was the worst. It started getting better during year 17. He has  Asperger's, so basically he is Sheldon.  He's not as disrespectful as he was at 15, but he can still have his moments.  Hang in there, This too shall pass.

I think it is pretty common but it may be more likely to happen because of the environment, or how you tend to react to his reactions. I think the type of response can make a big difference. Something like reflective listening at those moments (when he can't answer a simple question nicely, or when he talks back relentlessly, is so difficult & obnoxious--knowing everything & not seeming to appreciate any input) can dramatically change the way an interaction unfolds, and can change your overall experience of the relationship & child.
I have experienced this with my own kids & it makes sense, because it is about bringing more understanding of them to the equation (rather than reacting solely based on my own experience....of annoyance, of feeling offended or disrespected, etc.) A little empathy goes a long way.
I don't mean being "nice" or ignoring anything, but being able to have your feelings & acknowledge what's going

on for him (hear the emotional content of his edgy/irritated response, rather than focusing on the form it takes.)

If you're interested in exploring any of this, the book How To Talk So Kids Will Listen & Listen So Kids Will Talk is pretty easy to find in the public library system. Also Thomas Gordon's book Parent Effectiveness Training (P.E.T.) is readily available.
It's been awhile since I looked at How To Talk, but I think it begins with a pretty comprehensive description of the many ways our routine ways of hearing & talking to others are routinely (but unintentionally) negating, and the book is organized around describing a different way of hearing, listening & responding. It's simple to grasp & also simple to implement, but not always easy (because old patterns are ingrained & feelings/reactions drive them.) Being mindful & committed is the key.
The PET book offers the same stuff, which can transform teen relationships.