Obviously I don't know the situation, I can only give my two cents. If they work in CS2, they want someone who works in CS2. Then again, they might not have any other reason to give.
If you're not hired for a particular job, you could always ask the person who interviewed you why you weren't hired. The whole process of job hunting requires technique, strategy, persistence, deterimination, and a positive attitude. Every time you go on an interview, you might not be offered a particular position, but you are constantly networking, and although you may not get the exact job you applied for, that doesn't mean the opportunity for other opportunities stopped there.
Your resume obviously got you that particular interview. If you're not getting enough interviews, make sure you are sending out a lot of resumes. When you're job hunting, you could never send out too many resumes. The times I've hunted for jobs, I felt I was approaching it like no other human in the face of the earth. I probably sent out 100 resumes for breakfast, 100 resumes for lunch, 100 resumes for dinner, and 100 resumes as a midnight snack "every day".
If you feel your resume isn't a good representation of you, your career/background, or what you could do, your resume might need a makeover. If you feel your resume isn't saying really what you want to say to prospective employers about yourself, maybe it could use a rewrite.
Resume format isn't everything, but it's impressive when the layout, format, and language speaks to your audience, or your particular industry. For example, an RN's resume may have a different look and feel compared to a Software Developer/Programmer's resume. Although a resume is a form of a marketing tool, (marketing "you"), there is the interview process and follow-up.
Maybe there's nothing wrong with your resume. Maybe something comes up during the interview process.
Or maybe you do interviews great, and you just need to be more serious when it comes to "follow up."
Or maybe your resume is great, you're great at interviews, and you follow up with the works (thank you letters, 3 phone calls, and follow-up 1 to 3 months later or until that job listing comes down from the job bank).
What else could be wrong?
Maybe nothing! But maybe it's time to change job hunting strategies. Or maybe it's time to find other ways of getting visibility within your industry. For example, writing and publishing articles; improving or adding to your reel, portfolio, or website; going to industry tradeshows, conferences, and workshops; participating, demonstrating, or speaking at events; winning related-awards, competitions, and contests; working freelance, part-time, or on a contract-basis.
Job hunting really is a job in itself.
Maybe we should start a separate career/employment forum category. Lol.