In terms of "canonical ways" and "community approved libraries" here is what the current state looks like to me:
- as a substitute to something as low-level as numpy it is superb
- for anything dealing with differential equations, the ecosystem is unsurpassed
- plotting is a bit chaotic (and the community has not settled on a "one true way to plot")
- a good dataframe implementation already exists
- serialization is a bit chaotic (plenty of ways to do it but no "one true way" yet)
- automatic differentiation is on the cusp of being unsurpassed, but a lot of the tools are still experimental (and the community still has not settled on the best way forward)
- the Juno IDE looks amazing
- the profiling toolkit is amazing
- it is ridiculously easy to use other languages from within Julia