EPAM Systems Senior Software Engineer - Java Developer interview questions

In technical interview, I am asked the questions below; 1. Code reviewing. how to write clean code. 2. methodology, agile, how do you implement agile, which tools do you employ, deployment process etc. 3. OOP questions (inheritance, IS A, HAS A etc.), SOLID principles 4. which design patterns did you implement before 5. some Java specific questions about heap, memory JVM etc. 6. Collections API. HashMap, importance of hashCode and equals methods, how hashmap put a new entry and gets it (buckets) 7. Coding challenge: Given a non-negative number represented as an array of digits, add 1 to the number ( increment the number represented by the digits ). The digits are stored such that the most significant digit is first element of array.