The economics department at UBC is hiring 3 predoctoral students to work as full-time research assistants. Some of the positions will be more traditional economics work, but at least one of them will be heavy on computational methods, linear and nonlinear optimization, machine learning, etc. While I can’t promise it would all be in Julia, a decent proportion of the projects certainly would be.
While these are usually filled by students with a BA/MA in economics interested in getting into PhD programs, the technical position would also be a great way for a student from applied Math/OR/CS/Stats. to make the transition to academic economics or finance.