A system, apparatus and method process data by identifying a processing pipeline defining a series of markup language processing steps. The system inserts at least one debugging step into the processing pipeline. The debugging step(s) define processing to collect debug data associated with application of the markup language processing steps to markup language data to be processed by the processing pipeline. The system executes the series of markup language processing steps, including the debugging step(s), upon input markup language data as a transaction. Execution of the debugging step(s) captures the debug data for at least one of the series of markup language processing steps in the processing pipeline. The debug data allows analysis of operation of the markup language processing steps of the processing pipeline on the input markup language data.