[leminimal]

Thanks for linking me to that post! Its much better at expressing what I'm trying to say. I'll have a careful read of it now.

I think I'm still at a step before the overfit. It doesn't converge to a solution on its training data (fit or overfit). And all my data is artificially generated so no cleaning is needed (though choosing a representation still matters). I don't know if that's what you mean by getting the data right or something else. Example problems that "don't work": fizzbuzz, reverse all characters in a sentence.