Optaplanner project scheduling job similar to the employee rostering example on their page https://www.optaplanner.org/learn/useCases/employeeRostering.html
This project involves running optaplanner jar on aws lamda, I have similar implementation but optaplanner then runs as a service. the contraints and rules involves integration with google map service api or openstreet maps to get staffs location.
I will give more information when on call or chat via skype.
Regards