Relanto Python GCP Engineer interview questions

I was shortlisted for the Python GCP Engineer and in the JD they have clearly mentioned it is related to app development using Python, FastAPI/Flask, SQL , Mongo. The first round went well and I was able to answer the coding questions. The second round was fully focused on Data Engineering & ETL concepts. Why and how on earth someone can expect a app developer to answer questions related to data engineering, i clearly communicated it but still no hesistation from the interviewer asking further. The HR already sent a automatic rejection mail. Pathetic experience