<p>Tuning spin-orbit torque (SOT)-driven domain wall dynamics has attracted significant attention for advancing high-speed, low-power spin-based electronic devices. Conventional SOT-driven domain wall dynamics rely on spin injection from the bottom heavy metal /ferromagnet interface, where the Dzyaloshinskii-Moriya interaction (DMI) stabilizes chiral domain walls. However, the geometry inherently limits spin injection to a single direction, constraining the efficiency of domain wall motion and requiring high current densities for effective operation. Here, we introduce a lateral interface engineering strategy by incorporating heavy metal layers along the sidewalls of magnetic nanowires, which enables out-of-plane spin injection and generation of DMI at the side interfaces. Such multidirectional spin injection and DMI can enhance or suppress domain wall velocity, depending on the interplay between SOT and DMI-driven chirality. These results underscore the importance of lateral interface design in tuning SOT-driven domain wall dynamics and offer a promising framework for optimizing domain wall-based spintronic devices.</p>