Perpendicular magnetic anisotropy (PMA), spin pumping-induced damping, and interfacial Dzyaloshinskii–Moriya interaction (iDMI), which are spin–orbit coupling-related phenomena of utmost importance for applications, were experimentally investigated in as-grown and 225 °C annealed CoFeB/PtO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> , CoFeB/TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> , and Ta/CoFeB/TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> systems by means of vibrating sample magnetometry, microstrip ferromagnetic resonance, and Brillouin light scattering techniques. By varying Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">72</sub> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> (CoFeB) thickness in the range of 0.8–10 nm, the effect of Ta buffer layer on anisotropy and damping was first studied, where a large surface magnetic anisotropy ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K_{s}=2.1\,\,\pm \,\,0.16$ </tex-math></inline-formula> erg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) was measured in the unbuffered CoFeB/TaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> (0.8 nm) system most likely due to their higher roughness induced by the substrate. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K_{s}$ </tex-math></inline-formula> degrades significantly for CoFeB film thickness below 2 nm where spontaneous perpendicular magnetization was found to be impossible without Ta buffer layer. PMA, iDMI, and damping of as-deposited and 225 °C annealed CoFeB (1.5 nm)/PtO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> systems were measured as a function of PtO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> thickness in the range of 0.7–1.6 nm. Their strong dependence versus the PtO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> thickness was attributed to the decrease of the magnetic dead layer as PtO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> thickness increases. Linear dependence of damping versus PMA constant was obtained, confirming their relation with the spin–orbit coupling. Moreover, annealing increases PMA and the effective mixing conductance probably due to the enhancement of the CoFeB crystal structure and interfaces.