JWST MIRI simulated spectra for day- (top) and night-side (bottom) of WASP-103b with phase curve observations. Yellow points mark the simulated spectra and with colored areas we show the relative contributions of various species. SiO (in red) as a tracer of refractory elements, represents a promising window into a characterization of thermal inversions in ultra-hot-Jupiters as well as their origin.