Polymer is often considered one of the most prevalent materials in the modern age. While it has been predominantly synthesized in solution and processed into a variety of macroscopic sizes and shapes, the need for programmability in materials’ microscopic properties has challenged the traditional synthesis approaches. Recent advances in vacuum-based synthesis technologies, such as the initiated Chemical Vapor Deposition (iCVD) and Condensed Droplet Polymerization (CDP), have enabled a new mode of control over material properties during polymerization. Distinct from prior research that has placed a strong emphasis on the design of monomer molecular structure and controlled polymerization, the all-dry synthesis enables manipulation of the molecular interactions, such as molecular complexing and nanoscale dewetting, to achieve programmable nanoscale structures. In this talk, I will use two examples to illustrate the underlying principles and potential benefits of this distinct synthesis paradigm: (i) enabling vapor-phase molecular complexation during polymerization to achieve an unprecedented range of molecular weight, mechanical properties, and film morphology; (ii) leveraging nanoscale dewetting of nonpolar liquids to create polymeric nanodomes with spatiotemporal resolution on the nanoscale. Taken together, these advances in manipulating the physicochemical interactions during polymerization are poised to open up a new dimension in the design and synthesis of programmable polymeric materials, benefiting numerous existing and future technologies, ranging from nano-optics to drug delivery.