An Atomic Design developer builds digital interfaces using a methodology that breaks down design components into basic building blocks, similar to atoms in chemistry. They start with the smallest parts (atoms), like buttons or inputs, then combine them to form larger, reusable components (molecules), then further combine these to form templates (organisms). They focus on creating a scalable, consistent system that ensures uniformity across different parts of the project. They also ensure that the components are functional and aesthetic, while maintaining the flexibility to adapt to varying content and contexts. This approach promotes efficiency and consistency in design and development.