For the C++ frontend, there will be BC-breaking changes in v1.4 and v1.5 to make it behave more similar to the Python frontend, and we expect the core components (torch functions / tensor operators / autograd functions / NN functionals / NN layers / optimizers) to be mostly stable afterwards.
If by “deploying pytorch models in C++” you meant running JIT model inference in C++, @Michael_Suo would have more information about it.