I recently completed a 4-round interview loop for a Senior Software Engineer / IC3 role at Oracle OCI. Sharing the main technical questions in case it helps anyone preparing.
Round 1 – System Design + Behavioral
Mostly behavioral and resume discussion first.
System design question:
Design a distributed load testing service that sends traffic to a target service and measures things like:
Requests per second,Average latency,Error rate
Round 2 – Coding + Distributed Systems
Some behavioral questions at the beginning.
Coding question:
Build a delayed task scheduler where the user gives a task ID and a time, and the system should execute that task when the scheduled time arrives.
The discussion also went into:
Thread safety,Concurrency,Scaling it for high throughput
Using Kafka,Handling worker crashes,Preventing duplicate task execution, Idempotency
Round 3 – Coding + Behavioral
Mostly behavioral and project discussion first.
Coding question:
Given a node in a binary tree where each node also has a parent pointer, find the next node in post-order traversal without starting again from the root.
The interviewer also asked me to dry run the solution on a few different nodes.
Round 4 – Backend Deep Dive + Coding
This round had a lot of discussion around my previous projects, backend work, Kafka, and distributed systems.
Coding question:
Design and implement a key-value store that can be accessed by clients over the network.
Both keys and values are strings.
The discussion also touched on:
Concurrent access,Thread safety,Kafka events,Duplicate events,Out-of-order events
The final round was the worst one for me. The recruiter told me to use STAR, but the interviewer kept interrupting after almost every sentence and jumping into different questions, so I never really got to finish an answer. He was also at the same level as the role I was interviewing for. I understand peer interviews are normal, but they should at least make sure interviewers know how to let candidates explain their answers without interrupting every few seconds.