The overall process took over a month. It started with a brief call with the recruiter, followed by:

• Two telephonic phone screens, each one hour long.
• A Craft demo, which takes 3-4 hours to finish.
• Four hours of on-site interviews.

Sort 2 already sorted arrays into one array.

Serialize and deserialize binary tree.

Design LRU cache.

Internal working of Spark, especially joins, shuffles, etc. Differences between RDD, DataFrame, and Dataset.

Design a Big Data solution for 2 streaming datasets using any cloud or open-source technology.

Craft a demo, mostly demonstrating Spark working knowledge and distributed systems.