Note:  Domain-specific computing is promising for high-performance low-power execution of applications with similar functionality. In particular, streaming applications with significant functional and structural similarities can tremendously benefit. However, current Design Space Exploration (DSE) focuses on individual applications in isolation. Hence, much of the domain optimization opportunities are missed. DSE methodologies need to broaden the scope from individual applications in isolation to optimizing across applications within a domain.   This paper introduces a novel Domain-Specific DSE (DS-DSE) approach for domain-specific computing with a focus on streaming applications. Key contributions are: (1) a formalized method to extract the functional and structural similarities of domain applications, (2) a novel algorithm for hardware/software partitioning of a domain-specific platform to maximize the throughput across domain applications (under certain constraints) and (3) a methodology to evaluate a domain platform. This paper demonstrates the benefits using 4 domains: OpenVX (vision processing), and 3 synthetic domains (with greater complexity). Our experiments demonstrate a performance improvement (average throughput) of 36.8% for OpenVX and 46.2% for synthetic domains of the DS-DSE generated platform compared to an application-specific platform.