RBC Data Engineering interview questions

One interviewer at first, then another participated in after about 10 minutes. They were both kindly and inspired, happy to talk about the questions I cannot answer. We talked about my resume and project less than 10 minutes, then focus on Hadoop and Spark. Detailed about the internal mechanism. Then use Scala and Java to write simple code. Knowledge about database also asked, how to deal with two table join, and write code to join two tables and sort the keywords by Scala.