Emergent design is a consistent topic in agile software development, as a result of the methodology's focus on delivering small pieces of working code with business value. With emergent design, a development organization starts delivering functionality and lets the design emerge. Development will take a piece of functionality A and implement it using best practices and proper test coverage and then move on to delivering functionality B.
Emergent design is a recurring concept in agile software development because it aligns with the methodology's focus on delivering small functional pieces that provide business value. In emergent design, a development team starts by delivering a piece of functionality (A) and then continues to deliver more functionality (B), allowing the design to evolve organically as they work.