I miss the possibility of using the @code_warntype macro in other scope than the global one. The only moment I felt that something was taking more time with Julia than with Fortran was once I had a type instability that was hard to trace, and I had to run the pieces of code one by one until I reached the state of the system where the instability was actually manifesting itself in a function call. Since this is specific to Julia (relative to Fortran, at least), I put it in Julia’s account.
Otherwise everything else I find much better than previous workflows I had, including how easy is to distribute packages. And the final performance of my packages turns out to have improved relative to Fortran, mostly because it is easier and more fun to work on the code.