That part is true, but things like that are usually not too bad by themselves. For example, you can use open source tensorflow to access files on Google's inter

That part is true, but things like that are usually not too bad by themselves. For example, you can use open source tensorflow to access files on Google's internal filesystem with tf.io.gfile. It's possible other infra is somewhat hairy to decouple, for example the code they use to allocate and use GPU resources is internal. (I work on ML at Google and we use some of Deepmind's stuff)