Tech Mahindra interview question

Can you explain the differences between structured, semi-structured, and unstructured data? How do you design an ETL pipeline? What considerations do you take into account? What are the key components of a data warehouse architecture? How do you ensure data quality and integrity in your data engineering processes? Can you describe a project where you used big data technologies, such as Hadoop or Spark? What challenges did you face, and how did you overcome them?