Oracle Software Engineer Interview Experience — Six-Stage Onsite Loop from Brain Teasers to Bar Raiser

Stage 1

Coding Question
Max profit using a single buy and sell (best time to buy and sell stock, limited to one transaction).

Technical Question
Bottom view of a binary tree — explain the implementation approach and the reasoning behind it.

Technical Question
Find the minimum number of processes allocated.

System Design
Given a series of webpage URLs (including schemaName, host, port), design a video streaming system similar to YouTube/Netflix. Need to consider worldwide delivery.

Brain Teaser
There are three bags, containing gold coins, silver coins, and mixed coins respectively. All the bag labels are mislabeled. Given that you can only take one coin from one of the bags, how do you correctly relabel all the bags using just this one draw?

Behavioral

1. Why job switch
2. Describe a scenario where you had to make a decision with very little information
3. Are you willing to do full-stack development, e.g., take on both frontend and backend work

Stage 2

System Design
Design an enterprise-facing Remote Browser Isolation System. The discussion needs to cover: Authentication, Authorization, Data streaming, Gateways, Rate limiting, Virtual nodes, Edge server, etc.

Coding Question
Given a = 30, b = 40. Without using a third variable, swap the values of a and b.

Stage 3

Behavioral
Behavioral interview questions plus a deep dive into past projects.

Coding Question 1
To reduce the size of messages transmitted over the internet, implement a string compression algorithm that encodes consecutive repeated characters. Scan the string from left to right, grouping consecutive identical characters.

1. If a character appears only once, output the character itself.
2. If a character appears multiple times, output the character immediately followed by the count of its consecutive occurrences.
   For example, given the input aaaaabbbccca, output the compressed string according to this rule.

Coding Question 2
Given a sorted array of integers, remove duplicates in place so that each element appears at most k times.

1. Time complexity must be O(n)
2. Space complexity must be O(1)

Stage 4

Behavioral
A full one-hour behavioral interview with the Hiring Manager. Given specific scenarios to assess how you'd handle:

1. Conflict management
2. Handling tough people
3. Why Oracle
4. A discussion on how to use AI to optimize your own pet project

Stage 5

Behavioral
Bar Raiser interview, covering behavioral questions, why Oracle, and a detailed walkthrough of complex project experience.

Stage 6

Coding Question
Rate Limiter / Dropped Requests:
Given a sorted list of request timestamps, implement a function that returns the number of requests dropped according to the following limits:

• Maximum of 3 requests per second
• Maximum of 20 requests per 10 seconds
• Maximum of 60 requests per 60 seconds

Note: dropped requests still count toward subsequent rate limit quotas.

Follow-up:

1. Explain the different approaches, from naive to optimal.
2. Analyze time and space complexity.

System Design
Design a recommendation system for a large-scale e-commerce platform, based on the user's browsing history.