I am a Big Data Engineer with experience in scala and python Development for almost 2.5 years. In the first round of interview, the interviewer asked if I had core java experience. I told him that I am a scala developer and I know all the concepts of core java but I don't have experience in core java. He asked me to implement equals() method. I know how to implement CBC (cypher block chaining) for encrypted coming in streams and you are asking me to implement equals() method(it is lot easier than cbc). He said our requirement is for core java experience. He didn't even asked a single data engineering concept. I told him voluntarily I know how to handle data skewness in spark or hive. No bother from his side! I was rejected already.