  This paper tackles the deployment challenges of Simultaneous Transmitting and
Reflecting Reconfigurable Intelligent Surface (STAR-RIS) in communication
systems. Unlike existing works that use fixed deployment setups or solely
optimize the location, this paper emphasizes the joint optimization of the
location and orientation of STAR-RIS. This enables searching across all user
grouping possibilities and fully boosting the system's performance. We consider
a sum rate maximization problem with joint optimization and hybrid beamforming
design. An offline heuristic solution is proposed for the problem, developed
based on differential evolution and semi-definite programming methods. In
particular, a point-point representation is proposed for characterizing and
exploiting the user-grouping. A balanced grouping method is designed to achieve
a desired user grouping with low complexity. Numerical results demonstrate the
substantial performance gains achievable through optimal deployment design.
