I had a conversation with a hiring manager then received a data engineering challenge. The challenge consisted of two tasks: data modeling and programming. For data modeling I provided a designed schema in pdf files (facts, dimensions, relationships), description of designed tables and columns, ddls and sqls for metric calculations. For programming task I provided Python script, input and output files and two wrappers to run the Python script in Linux and Windows. After couple of days I received an email with the rejection if a form of standard explanation to proceed with other candidates. It's more than a year had passed since then and recently I found out that they put a permanent hiring ban on me. It's really weird that a company puts such permanent ban for just the engineering challenge.