The Mu3e experiment is searching for the charged lepton flavour violating decay \( \mu^+\rightarrow e^+ e^- e^+ \), aiming for an ultimate sensitivity of one in \(10^{16}\) decays. In an environment of up to \(10^9\) muon decays per second the detector needs to provide precise vertex, time and momentum information to suppress accidental and physics background. The detector consists of cylindrical layers of \(50\, \mu\text{m}\) thin High Voltage Monolithic Active Pixel Sensors (HV-MAPS) placed in a \(1\,\text{T}\) magnetic field. The measurement of the trajectories of the decay particles allows for a precise vertex and momentum reconstruction. Additional layers of fast scintillating fibre and tile detectors provide sub-nanosecond time resolution. The MuPix8 chip is the first large scale prototype, proving the scalability of the HV-MAPS technology. It is produced in the AMS aH18 \(180\, \text{nm}\) HV-CMOS process. It consists of three sub-matrices, each providing an untriggered datastream of more than \(10\,\text{MHits}/\text{s}\). The latest results from laboratory and testbeam characterisation are presented, showing an excellent performance with efficiencies \(>99.6\,\text{\%}\) and a time resolution better than \(10\, \text{ns}\) achieved with time walk correction.