The LHCb measurements of $R_{K}$ and $R_{K^{*}}$ indicate a breaking of lepton flavour universality in rare decays of beauty hadrons.
They point to a deficit of decays mediated by a $b\rightarrow s \mu\mu$ transition, with respect to those mediated by a $b\rightarrow s ee$ transition. It is especially intriguing since several other observables in $b\rightarrow s \mu\mu$ decays show discrepancies with respect to their Standard Model predictions, and all these anomalies point to a consistent New Physics interpretation. I will give an overview of these various anomalies and their implications, and discuss the experimental challenges of their measurements, focusing especially on the LHCb measurement of $R_{K}$. I will also present what are the future plans, mainly at LHCb, to tackle these anomalies and understand their origin.