I can’t speak for AAA studios but I can (try to) tell how’s the life of a TA in a 10-15 people indie studio.
You’re not a real, focused on a field, TA: you’re and you’ll be for a long time a real jack of all trades, just like Steve said.
There is no “pipeline” TA, or “character TA” or whatever: there is “just” a person that is not 100% artist and not 100% programmer, and his/her job is to take care of everything that fall in this grey area.
That’s it.
One week you could work on a bunch of shaders and the next one you could rig a character. And maybe in the middle you also had to profile the game and understand why it runs at 12 fps .
Sometimes it’s very exciting because you really feel that there is a specific problem to be solved by you, and since you’re not a real specialist, problems will vary a lot: this helps to keep enthusiasm and curiosity high.
But sometimes it could be boring because,in a small studio, you will rarely face huge problems, and when there aren’t problems at all there is no huge pipeline or toolset to maintain. So you could end doing just small production tasks.
The up is that the environment will be probably very dynamic, informal and friendly.
One downside could be that you could work on uninteresting project: can’t speak for every small studio here but my experience is that “bills need to be paid”: this means that sometimes the game-of-our-dream must be put on hold and some other “b2b” not fun project must be done.
If this goes for a long period and if you can’t find the good in these projects, it could be bad for morale.
This actually was for me one of the major problems I had to cope with in years (together with money problems).
Oh, there is another pros btw: you could probably propose ideas and even “invent” your own tasks sometimes.
Maybe a small studio doesn’t have some toolset or pipeline and you, coming from a bigger and more structured company, could bring these improvements to the team: it’s something I try to do whenever I can… Learn from TAO folks and apply here!
My 2 (and a always verbose) cents