How do you build Rek'sai?

I know she's getting nerfed next patch, but I've been playing her a bit and I'm never sure if I'm making much of an impact in fights. Sure I can knock people up, but I can only do that in the beginning (I'm not great with her) and beyond that I don't feel I'm doing enough damage or surviving long enough to do anything.

When I first played her (back when she was released) I used to get ravenous hydra for sustain and clear (combined with Visage to increase her sustain). But people keep recommending Titanic, which honestly doesn't feel like a great option to me (I don't try to build her with massive amounts of health, so I don't see the benefit. I want to have her be durable, but not a tank).

Is it a waste of time to build sustain for Rek? Should I just build juggernaut instead of bruiser?