I have recently posted the following question on MO: "Approximation with Predefined Topology of Niveau Sets", which received close to zero attention.
Igor Khavkine was so kind to make me aware of scicomp.stackexchange.com, which also would have been appropriate place for posting my problems, however, I am a bit ambivalent about how to proceed.
Mathoverflow seems to me to be the more overarching forum for "advanced-level-mathematics", so it might be in the interest of the MO community to also be presented non-trivial practical problems even though the chances of getting more attention on a specialized site like scicomp.stackexchange.com would be bigger.
The major options I see, would be to
present problems that also have a strong computational aspect on MO first and migrate them if they don't receive enough feedback
present such questions simultaneously to both forums and provide cross-links between the sites
only post on the site that seems more suitable in terms of expected feedback
Questions for discussion:
which of the above (or other) options would be an appropriate choice, in view of the fact that the relation between MathOverflow and Computational Science is not a hierarchical one as between MathOverflow and SE Mathematics.