EPAM Systems Interview Questions, Process, and Tips

Merge 2 sorted lists in O(n) time complexity.

• Use two pointers to iterate through both lists simultaneously.

• Compare elements at the pointers and add the smaller one to the result list.

• Move the pointer of the list from which the element was added.

• Repeat until all elements are merged in sorted order.

Singleton class to allow only 5 objects, report error for 6th

• Create a private static variable to hold the instances of the class

• Create a private constructor to prevent external instantiation

• Provide a static method to access the singleton instance and limit the number of instances to 5

• Throw an error when trying to create the 6th instance

Use a boolean array to track presence of each alphabet in the sentence.

• Create a boolean array of size 26 to track presence of each alphabet.

• Iterate through the sentence and mark the corresponding index in the array as true.

• Check if all elements in the array are true to determine if sentence has all alphabets.

The microservices architecture is the best architecture I have seen so far.

• Scalability: Allows for independent scaling of different components

• Resilience: Failure in one service does not bring down the entire system

• Flexibility: Easier to update and deploy new features

• Decentralization: Each service can be developed and deployed independently

Java OOPS concept focuses on creating classes and objects to model real-world entities.

• Encapsulation: Bundling data and methods that operate on the data within a single unit (class)

• Inheritance: Allows a class to inherit properties and behavior from another class

• Polymorphism: Ability of a method to do different things based on the object it is acting upon