1. A computer-implemented method to determine data quality issues in data processing jobs, the method comprising: receiving a data processing job specifying one or more processing steps designed based on one or more data schemas and further specifying one or more desired quality metrics to measure at the one or more processing steps; providing one or more state machines generated based on the quality metrics and on the data schemas; processing input data for the data processing job by operation of one or more computer processors and using the one or more state machines, in order to generate output data for the data processing job and a set of data quality records characterizing a set of data quality issues identified during execution of the data processing job; and outputting the generated set of data quality records.