While the production of bosons during inflation has received substantial attention, the production of fermions has often been neglected. Fermions can be produced via a derivative coupling during axion inflation; in this talk, I will present recent calculations illustrating phenomenologically interesting consequences. In particular, the CMB power spectrum fluctuations can be dominated by the sourced contribution while satisfying non-Gaussianity constraints, in contrast to bosonic production. Time permitting, I will also discuss recent results on the gravitational wave signal in this model.