The overall goal is to create something that is a useful/valuable addition to the ecosystem while improving our Haskell skills.
Sounds great! Fortunately Gabriella Gonzales has cut some work for you. How about looking to fill some loophole, a place where Haskell is less than great as of now? Of course it all depends on your team’s interests and strengths.
A personal suggestion to complete the list: the list does not mention “web crawlers” (which are probably a joy to implement in Haskell), nor the fact that finding libraries nowadays on Hackage / Stackage can be a real pain (I’d surmise that poor visibility and lack of documentation are the most significant blockers to Haskell’s growth in the industry). Perhaps there is something to be done in the form of a web crawler that would spot missing / insufficient documentation in libraries? Or some sort of search engine specialized for libraries?
edit: Also making a tool to help find open-source Haskell projects in need of contributors / maintainers would greatly help. There is this lovely idea put to use here already: https://github.com/haskellfoundation/matchmaker