Possible jobs areas after math doctorate

A friend of mine finished her maths doctorate and worked in a startup for 3D renderings. Unfortunately the positions was discontinued. They are looking for jobs where maths plays part in the daily routine. But would like something different then statistics or optimizations.

Which industries, fields or institutions would offer or require such topics?

I am trying to find possible work areas and help her, but my industry knowledge only applies to a small field not related to maths.