Electronic(s) design automation (EDA) is a field where Tcl has traditionally had a strong presence. John Ousterhout originally created Tcl in the late '80s as an extension language for EDA applications which were his professional focus. [Drop names--Mentor, ...]
Jonathon Bromley recommands "Tcl for EDA" [L1 ] and his employer's technical Web site [L2 ] as informative.
Tcl's strength in testing is an advantage for its use in EDA.