10-20 years out is far enough out that I am not sure what will be happening and that there will even be the concept of web development. In the next 1-2 years though, yes, I do think it is will be very common to use AI APIs. A great example is iOS and the CoreML framework, the iOS developer may not be the person training the Machine Learning model, but they know enough about it to use the model in the their application. My suspicion is much of the hard stuff in AI is going to be commodity: hyper parameter tuning, model selection, etc, and there will be tremendous value in people who can create solutions with AI APIs.
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