How to make tofu that is crispy and flavorful outside and soft inside? I know how to fry tofu to make it firm, and also how to dry fry it and marinade it to make it flavorful.  Neither of these cooking techniques mimics the tofu I get at my local Thai restaurant.

When I order tofu there, it is perfectly fried to give it firm texture on the outside, but when you bite in, it's juicy and melts in your mouth, making the tofu experience much better.  It literally blends with the other flavors this way and I can't figure out how they do it.  I'll also note that the inside is not seasoned, it's the internal texture that makes it taste so good.

Is it the type of tofu maybe?  Or the frying time?  Any ideas?
Most likely, they are using a softer tofu than you.

For whatever reason, the US is infatuated with unusually firm tofu, and supermarkets emphasize the "extra firm" varieties. In Asia, especially Japan and Korea, but even in China, most applications call for a softer, more custard-like tofu.

If it's soft inside, when you deep fry the tofu, it should stay fairly soft inside. The cornstarch or potato starch you coat it with will make the outer bits crispy.