This paper presents a method for computing one-loop amplitudes in massless supersymmetric gauge theories using unitarity. The authors show that a large class of one-loop amplitudes can be determined solely from their cuts, which are derived from tree-level amplitudes. This method is applicable to both supersymmetric and non-supersymmetric theories. The key result is that all color-ordered amplitudes in massless supersymmetric gauge theories with trivial superpotential are cut-constructible, meaning they can be determined from their cuts. The method is demonstrated for N = 1 and N = 4 supersymmetric gauge theories, where the authors compute the one-loop amplitudes for n-gluon scattering in N = 1 supersymmetric theories and for six-gluon scattering in N = 4 supersymmetric theories. The paper also discusses the application of this method to non-supersymmetric theories, where certain contributions can be determined from cuts. The authors show that the method is robust and can be used to compute amplitudes with a wide range of helicity configurations. The paper concludes that the method is a powerful tool for computing one-loop amplitudes in both supersymmetric and non-supersymmetric gauge theories.This paper presents a method for computing one-loop amplitudes in massless supersymmetric gauge theories using unitarity. The authors show that a large class of one-loop amplitudes can be determined solely from their cuts, which are derived from tree-level amplitudes. This method is applicable to both supersymmetric and non-supersymmetric theories. The key result is that all color-ordered amplitudes in massless supersymmetric gauge theories with trivial superpotential are cut-constructible, meaning they can be determined from their cuts. The method is demonstrated for N = 1 and N = 4 supersymmetric gauge theories, where the authors compute the one-loop amplitudes for n-gluon scattering in N = 1 supersymmetric theories and for six-gluon scattering in N = 4 supersymmetric theories. The paper also discusses the application of this method to non-supersymmetric theories, where certain contributions can be determined from cuts. The authors show that the method is robust and can be used to compute amplitudes with a wide range of helicity configurations. The paper concludes that the method is a powerful tool for computing one-loop amplitudes in both supersymmetric and non-supersymmetric gauge theories.