The proposed major upgrade of the LHCb detector for LHC Runs 5 and 6 aims to enhance the precision of flavor-physics observables significantly. Known as Upgrade II, this initiative is scheduled for implementation during the long shutdown 4 of the LHC. The upgraded detector is designed to operate at a maximum luminosity of $1.5 \times 10^{34} \, \text{cm}^{-2}\text{s}^{-1}$, targeting an integrated luminosity of approximately $300 \, \text{fb}^{-1}$ over the lifespan of the high-luminosity LHC (HL-LHC). The ambitious goals of this upgrade demand the maintenance of the current detector performance, even in the face of an expected average number of simultaneous proton-proton collisions per bunch crossing (pileup) of around 42 which will be 7 times that of Run 4. To meet this challenge, the plan includes the replacement of all existing subdetector components to enhance granularity, reduce detector material, and incorporate new technologies, such as precision timing at the scale of a few tens of picoseconds. Here we discuss design considerations for each sub-detector, ongoing efforts to address technology challenges, goals and performances of LHCb upgrade II.