As a member of the ATLAS Collaboration at the Large Hadron Collider, I work on experimental tests of the electroweak sector of the Standard Model (SM) of particle physics. My work focuses on precision measurements of the production rates of pairs of gauge bosons (mainly Z boson pairs, but more recently the production of a Z boson together with a photon). These measurements not only test the SM (providing indirect limits on possible new physics beyond the SM) but are also important in connection with studies of the Higgs boson, for which gauge boson pairs are the primary source of background. An offshoot of this work, also relevant to Higgs physics, was the observation of the rare decay of the Z boson to four charged leptons and a measurement of its branching ratio.