Oracle IC4 Phone Screen Experience

Introduction

The interview began with a detailed walkthrough of my background, from my college days to my current role. The interviewer performed a deep dive into my resume, asking about every tool and technology I had mentioned. I also had to provide a high-level overview of my current project architecture and my specific responsibilities within it.

OOP & Design Principles

This section focused on core Object-Oriented Programming (OOP) and design principles. I was asked to explain each of the SOLID principles in depth. Following that, we discussed the differences between Abstract Classes and Interfaces, with a specific request to provide real-world, non-programming examples to illustrate my understanding.

REST API Concepts

The discussion moved to REST API concepts. I had to explain the differences between PUT, PATCH, and POST methods, including when and why each should be used. The interviewer then delved into the OPTIONS HTTP method, asking about its purpose and how it's used, particularly in scenarios like CORS preflight requests.

Low-Level Design & Patterns

I was challenged to design a system using Object-Oriented Design (OOD) principles and various design patterns. The expectation was to provide both code and a strong explanation, with a focus on clarity, modularity, and how the design mapped to real-world scenarios.

DSA Coding – Live Problem on HackerRank

This was the live coding section, where I had to solve a Data Structures & Algorithms (DSA) problem on HackerRank. The problem involved an array and 'k' operations, where in each operation, I could pick any number and divide it by 2. The goal was to perform up to 'k' operations to minimize the total array sum. I approached this using a max heap (priority queue) to continuously halve the largest number for 'k' times. I successfully implemented it and passed all test cases.

Database Design Discussion

We then discussed database design, specifically comparing SQL and NoSQL databases. I explained when to use each, their respective pros and cons, and touched upon the CAP theorem tradeoffs.

AI/ML Discussion

Briefly, I was asked if I had worked with AI/ML models or pipelines, and I shared any related experience I had.

Architecture Diagram

Finally, I was asked to verbally describe or sketch a high-level system architecture, with the focus on scalability, modularity, and deployment pipelines.

Final Thoughts

Overall, I felt I answered around 85–95% of the questions confidently. The interviewer was thorough, at times challenging even basic concepts deeply, but remained respectful throughout. Unfortunately, the recruiter never followed up after the round, despite my attempts to reach out.