How would you - on-the-fly - prevent a neural network from overfitting using a Keras callback? I have a neural network that starts to overfit in that the validation loss begins to increase while the training loss stays ~ flat with epochs.

Is there a generic algorithm - obvious or otherwise, well-known or not - to stop the training early if overfitting is somehow detected?

I note that catboost implements such an algorithm but I have found it nowhere else.

https://catboost.ai/docs/concepts/overfitting-detector.html

Is this all simply a matter of rolling my own callback function and stopping when the training and validation losses start to diverge..?

Preference for TF, Keras, python3, ...

Thanks as ever
Sounds like you're just looking for EarlyStopping, which will stop training when validation loss does not improve for N epochs. It's the same as Iter in catboost.