A data architect is a practitioner of data architecture, a data management discipline concerned with designing, creating, deploying 
and managing an organization's data architecture. Data architects define how the data will be stored, consumed, integrated and managed by different data entities and IT systems, as well as any applications using or processing that data in some way. It is closely allied with business architecture and is considered to be one of the four domains of enterprise architecture.
Role
According to the Data Management Body of Knowledge, the data architect “provides a standard common business vocabulary, expresses strategic data requirements, outlines high level integrated designs to meet these requirements, and aligns with enterprise strategy and related business architecture.”
According to the Open Group Architecture Framework (TOGAF), a data architect is expected to set data architecture principles, create models of data that enable the implementation of the intended business architecture, create diagrams showing key data entities, and create an inventory of the data needed to implement the architecture vision.
Responsibilities
Organizes data at the macro level.
Organizes data at the micro level, data models, for a new application.
Provides a logical data model as a standard for the golden source and for consuming applications to inherit.
Provides a logical data model with elements and business rules needed for the creation of data quality (DQ) rules.
summarize the responsibilities of a data architect
a data architect defines how data is collected, processed, stored,  consumed, and integrated within different data entities and IT systems within an enterprise.
a data architect defines a common business vocabulary to be used across the enterprise 
a data architect expresses strategic data requirements and provides high-level designs to meet the end business architecture 
a data architect creates data models showing key entities, and relationships between entities.