Depending on their preparation, amorphous materials display different types of behavior under shear when passing from an elastic regime to a plastic one. This passage, known as the ”yielding transition” can happen in a smooth way or in a sudden, catastrophic manner. This strongly depends on the preparation of the sample, and in particular on the annealing which it undergoes and which controls the initial disorder. The transition between a smooth (ductile) and a discontinuous (brittle) behavior is reminiscent of the one observed in quasi-statically driven Random Field Ising Model (RFIM) at zero temperature, where the magnetization can either undergo a macroscopic jump or smoothly vary when an applied magnetic field is slowly increased.