  The recent determination of the $\beta$--function of the QCD running coupling
$\alpha_{\overline{MS}}(Q^2)$ to 5-loops{\color{blue},} provides a verification
of the convergence of a novel method for determining the fundamental QCD
parameter $\Lambda_s$ based on the Light-Front Holographic approach to
nonperturbative QCD. The new 5-loop analysis, together with improvements in
determining the holographic QCD nonperturbative scale parameter $\kappa$ from
hadronic spectroscopy, leads to an improved precision of the value of
$\Lambda_s$ in the ${\overline{MS}}$ scheme close to a factor of two; we find
$\Lambda^{(3)}_{\overline{MS}}=0.339\pm0.019$ GeV for $n_{f}=3$, in excellent
agreement with the world average, $\Lambda_{\overline{MS}}^{(3)}=0.332\pm0.017$
GeV. We also discuss the constraints imposed on the scale dependence of the
strong coupling in the nonperturbative domain by superconformal quantum
mechanics and its holographic embedding in anti-de Sitter space.
