I received a call through a third-party recruiter, and an interview was arranged two days later with SAP. There were two F2F technical rounds and one project manager round. The interview was completed in one day, and I received an offer.

Round 1:

• '==' vs equals() method in Java.
• Contract between equals() and hashCode().
• HashMap vs ConcurrentHashMap.
• Volatile keyword and atomic in multithreading.
• Synchronize keyword and implementation.
• Exception vs Error in Java.
• SQL: Find nth highest salary from emp table.
• Find manager of an employee from employee table (self-join using id).
• LIKE operator in SQL queries, indexing. etc...

Round 2:

• Java 7 vs 8 (Interfaces).
• Why Functional Interface when Abstract Class is available in Java 8?
• Default methods in Java 8.
• Lambda Expressions.
• Write code to find if a given equation is balanced or not (hint: can solve using stack).
• Find loop in a LinkedList if it exists.
• Find the substrings of length 'K' in a given String and arrange them lexically.
• Design Relational DB for Student, Course, and Subject tables.