As a predominant design method for microsservices architecture (MSA), domain‐driven design (DDD) utilizes a series of standard patterns in both models and implementations to effectively support the design of architectural elements. However, an implementation may deviate from its original domain model that uses certain patterns. The deviation between a domain model and its implementation is a type of architectural drift, which needs to be detected promptly. This paper proposes an approach, namely DOMICO, to check the conformance between the domain model and its implementation, by which the conformance is formalized by defining eight common structural patterns of domain modeling and their representations in both models and the corresponding source code. Based on the formalization, our approach can not only identify the discrepancies (e.g., divergence, absence, and modification) with respect to pattern elements, but also detect possible violations of 24 compliance rules imposed by the patterns. To validate DOMICO, we performed a case study to investigate its use in a supply chain project and its performance. The results show that DOMICO can accurately identify 100% inconsistency issues in the cases examined. As the first conformance checking approach for DDD, DOMICO can be integrated into the regular domain modeling process and help ensure the conformity of microservice implementations to models.