  Since April 2020, the SuperKEKB has been operating with the crab waist
scheme. The luminosity record achieved in June 2022 was $4.71 \times 10^{34}
\text{ cm}^{-2}\text{s}^{-1}$, which overtook its predecessor KEKB by more than
a factor of 2. The beam-beam interaction plays a key role in causing vertical
blowup and consequently limiting the luminosity performance of SuperKEKB. In
this paper, we examine luminosity tunings under the influence of beam-beam
effects and review the luminosity performance of SuperKEKB with the crab-waist
operation from 2020 to 2022.
