Prototype with Perl, Ruby, Python, Tcl, etc and to optimize you have to dive into using an FFI (foreign function interface).
Prototype with a Unix/Linux shell (bash, ash, ksh, etc) and to optimize you rewrite proc/commands in your favorite (compiled?) language and use stdin/stdout as the interface.
When piping makes sense (or concurrent processes with lightweight I/O requirements), 30+ years of shell wisdom is your friend.
If shell scripts can be trusted to boot your Unix/Linux distribution, can the shell be trusted as the controller/glue for your application?