Design Technology Co-Optimization (DTCO) becomes more important with every new technology node. Complex patterning issues can no longer wait to be detected experimentally using test sites because of compressed technology development schedules. Simulation must be used to discover complex interactions between an iteration of the design rules, and a simultaneous iteration of an intended patterning technology. The problem is often further complicated by an incomplete definition of the patterning space. The DTCO process must be efficient and thoroughly interrogate the legal design space for a technology to be successful. In this paper we present our view of DTCO, called Design and Patterning Exploration. Three emphasis areas are identified and explained with examples: Technology Definition, Technology Learning, and Technology Refinement. The Design and Patterning Exploration flows are applied to a logic 1.3x metal routing layer. Using these flows, yield limiting patterns are identified faster using random layout generation, and can be ruled out or tracked using a database of problem patterns. At the same time, a pattern no longer in the set of rules should not be considered during OPC tuning. The OPC recipe may then be adjusted for better performance on the legal set of pattern constructs. The entire system is dynamic, and users must be able to access related teams output for faster more accurate understanding of design and patterning interactions. In the discussed example, the design rules and OPC recipe are tuned at the same time, leading to faster design rule revisions, as well as improved patterning through more customized OPC and RET.