"What do you produce?"
I oversee design and development of digital products for children. I also write novels for children (one published so far, the first in a series).
"How did you get started doing it?"
I discovered digital media ages ago and dove into it like a good INTP, learning everything I could about the specific sub-section I'd just started working in. The field changed so quickly that I never got bored, and I was able to reinvent my career every few years while staying essentially on the same trajectory.
As for the writing, that's just something I always did.
"How does your INTPness empower you in it?"
I think in general that writing is a good hobby or career for an INTP. Architecting the story, then diving into the research to learn every detail about some tiny thing that's just on one page of the novel. It's an area where you can really follow your intellectual curiosity. Actually finishing a book can be a real challenge, though. It can also be challenging to avoid the instinct to rewrite the whole book based on some new idea that just occurred to you. And (at least for me) I have to remind myself to spend sufficient time on the characters' emotions and relationships.
And I discovered that worldbuilding is an even better fit for an INTP. I write science fiction and fantasy, so it involves a lot of worldbuilding. Inventing future world scenarios, crafting entire cultures, and so on. You can just follow it wherever it leads, all the while keeping all the pieces together in your head. When you change one variable in the world, you have to be able to follow all the connected paths and make any necessary adjustments. INTPs are particularly good at that sort of thing, I think.
As for digital product development, my INTPness comes in handy when I'm translating business parameters into product concepts, and then again when I'm architecting the products, juggling the design, technology, and content as part of a single, unified vision. I do find myself trying to unify things that don't really need to be unified, but the instinct is generally a plus in product development.