The performance of multispecific antibody therapeutics is largely determined at the discovery stage. VHHs provide unique structural and biophysical advantages for complex molecular architectures, but their impact depends on the diversity and functional quality of the starting repertoire. This presentation will highlight how we generate high-diversity, in vivo-derived VHHs to enable broad epitope coverage, improved developability profiles, and increased engineering flexibility for bi- and multispecific formats. We will also share how our discovery platform is applied to GPCRs, ion channels, and other challenging membrane protein targets to expand optionality and support successful multispecific program development.