<p>To expand on the on-topic side of @whubers answer:</p>

<p>Firstly, there are applications of optimization that are on topic here: both optimization applied to the "usual" fitting of models and hyperparameter optimization. </p>

<p>Secondly, I think one fundamental difference between CV and more "mathematical"  sites is that stats is about noisy data. In contrast most optimization heuristics I'm familiar with assume well behaved smooth target functions. So I'd also conster questions about <em>optimization of noisy target functions</em> on topic. </p>
