expressions - What is a better way to say "computer person with a lot of experience in multiple parts of computer-related areas"?

For any kind of "formal" context, I doubt terms like computer guru/veteran would be suitable.

Assuming OP particularly wishes to convey the three specific areas in which he has extensive experience, perhaps...

I have experience across a broad range of languages, applications, and team roles.

Personally, I'd be inclined to add (up to and including managing teams), because many people might assume team roles only goes up to team leader at best - and I personally would say that's a considerable step below manager.