Lepton reconstruction performance plays a crucial role in the measurement precision and new-physics search sensitivity of the Large Hadron Collider (LHC) data analysis of the ATLAS experiment. The 139 fb$^{-1}$ of proton-proton collision data collected during the LHC Run-2 introduce both a challenge and an opportunity for detector performance studies. Using di-electron and di-muon resonances we are able to calibrate to sub per-mil accuracy the detector response for electrons and muons. This talk will present recently released results significantly improving the measurement of lepton reconstruction, identification and calibration performance with innovative techniques. New analysis techniques are exploited which involve multivariate analyses for rejecting background hadrons that mimic prompt leptons from the hard interactions as well as innovative in-situ corrections on data that reduce biases induced by residual detector displacements in muon momenta measurements. These improvements can further help extend the reach of ATLAS physics program.