The first round was a screening call to get to know you. The second round was a technical round where they asked about pointers vs references, pass-by-value vs pass-by-reference, immutability, difference between Java and Python, OOP and its principles, JVM, memory management, garbage collection (know it and be able to implement pseudocode!). That's where it ended for me. My suggestion is to focus on the fundamentals - know how something works, why it works, what changes when you don't implement it the way you are supposed to, so you don't get tripped up if they ask a question in a different way.
The coding questions are relatively easy - reverse an array, filter words from an array using another array, writing hello world code then explaining what the syntax means