The complexity of traditional front-side heterogeneous integration techniques is limited by thermal budgets, large surface topology, and the need to have the III-V in close proximity to the silicon. This talk introduces SCINTIL Photonics’ BackSide-on-Buried Oxide (BSoBOX) platform, process flow, and device demonstrations. In the BSoBOX method, the pre-formed silicon photonics (SiPh) wafer is flipped and bonded to a silicon handle wafer. The original substrate from the SiPh wafer is then removed, leaving a flat, thin BOX layer. Lastly, III-V is bonded and patterned onto the thin BOX. This enables III-V integration on SiPh platforms of arbitrary complexity.