This is in some sense a follow up to the question asked here [Properties of the category of compact Hausdorff spaces][1] To clarify: The category $\text{Prof}$ of profinite sets sits inside the category $\text{CHaus}$ of compact Hausdorff spaces in a nice way. Every compact Hausdorff space $X$ can be covered by a profinite set (specifically the stone Czech compactification of the underlying set of $X$). $\text{Prof}$ can be characterized by a universal property without reference to the category of topological spaces: It is the free completion of the category $\text{Fin}$ of finite sets under cofiltered limits. Since $\text{CHaus}$ is, unlike $\text{Top}$, a category that is quite nicely behaved (it is for example the category of algebras for the ultrafilter monad on sets), it seems natural to ask: Can it also be characterized as a category by a universal property similar to $\text{Prof}$? [1]: https://mathoverflow.net/questions/382348/properties-of-the-category-of-compact-hausdorff-spaces