The LHCb experiment underwent a major upgrade of its detector for the ongoing third run of data taking at the LHC. A key feature of this upgrade is the complete redesign of the data acquisition chain that allows to run a fully software-based high-level trigger system at a rate of 30 MHz in real time. The two stages of the high-level trigger are implemented on a hybrid architecture of GPUs and CPUs and perform the full event reconstruction, real-time alignment and calibration and event selection. The removal of the previously operated hardware trigger stage ensures higher trigger yields especially for electron and fully hadronic decay channels as well as charm physics. The selective persistence of the Turbo model in the second trigger stage enables high flexibility in the event selections that is necessary to cover the demands from the various corners of the broad LHCb physics programme. These proceedings highlight the major challenges in the implementation of upgraded trigger system, the role of monitoring during its operation as well as its first results from the third run of LHC data taking.