As a developer, I can share my code with my Vagrant box via NFS instead of rsync
Vagrant can share the code with the guest using NFS, but I was not able to get it working when getting us started with Vagrant. For some reason, Vagrant was trying to use /etc/init.d/nfs to start NFS instead of systemctl. I haven't dug into the issue any further, so I cannot suggest a solution here yet.
beav suggested that there may be firewall issues to overcome as well.