Como se preparar para entrevistas na Oracle

+15

Tell me about a time you had a conflict with a coworker. How did you resolve it?

+14

What project are you most proud of?

+7

Tell me about a project where the requirements were not clear or kept changing. How did you adapt and maintain productivity?

+6

Design a Top-K System

Design a system that efficiently retrieves top-k items (songs, videos, hashtags, etc.) based on user activity or engagement metrics within specified time windows. The system should handle real-time data aggregation and support queries like "top 10 songs in the last 7 days" or "trending hashtags in the past 24 hours."

+5

Design a Hotel Booking System

Design a hotel booking system that allows users to search for hotels, make reservations, and manage bookings. Focus on data modeling and SQL queries for handling room availability, pricing, and reservation management.

+5

Design a URL Shortener

Design a URL shortening service similar to TinyURL that allows users to convert long URLs into short, shareable links and manage their shortened URLs.

+5

Design a Rate Limiter

Design a rate limiting system that can control and throttle API requests to prevent system overload and ensure fair resource allocation. The system should be able to handle distributed scenarios, track requests across multiple servers, and enforce limits per user/client or between internal services to prevent abuse and maintain system performance.

+5

Leetcode 146. LRU Cache

Implement an LRUCache that supports O(1) average-time get(key) returning the value or -1 and put(key, value) which inserts or updates a key and, if capacity is exceeded, evicts the least-recently-used key. The core challenge is maintaining key-value storage together with recency ordering to enable constant-time access, updates, and eviction.

+4

Give an example of a situation where you had to overcome a significant setback or obstacle to achieve a goal

+4

Describe a time you failed and how you managed the situation

+4

Design a Notification System

Design a scalable notification system that supports both individual and bulk notifications to multiple users. The system should handle different types of notifications including critical time-sensitive messages (like 1:1 chat) and promotional content (like system-generated recommendations) with appropriate delivery mechanisms. Consider scalability requirements (up to 1M notifications/second), expiration logic for different notification types, and the typical 80/20 distribution between critical and promotional notifications where promotional messages can target thousands of users simultaneously.

+4

Design Instagram

Design a photo-sharing social media platform where users can upload photos, follow other users, and view a chronological feed of posts from people they follow.

+2

Tell me about a project of your choice and its challenges

+2

Design Uber

Design a ride-sharing service like Uber that allows users to request rides, matches them with nearby drivers, handles real-time tracking, and processes payments.

+2

Leetcode 200. Number of Islands

Count the number of islands (4-directionally connected components of '1's) in an m×n binary grid. This is a connected-components/flood-fill problem typically solved with DFS/BFS or Union-Find in O(mn) time (m,n ≤ 300).

+1

Discuss a time when you had conflicting perspectives with teammates and how you handled it

+1

Describe your current role

+1

Describe a project with unclear or changing requirements and your approach to maintaining productivity.

+1

Leetcode 347. Top K Frequent Elements

Given an integer array and k, return the k most frequent elements — the core challenge is to count element frequencies and extract the top-k efficiently (better than O(n log n)), typically using a frequency map combined with a min-heap (O(n log k)) or bucket sort (O(n)).

+1

Design a Distributed Cache System

Design a distributed caching system that can serve data with low latency across multiple geographic locations, handling cache misses, replication, and scaling to support billions of records.

+1

Design a News Aggregator System

Design a news aggregation system like Google News that allows users to subscribe to different news sources, categories, and topics, then view a personalized real-time news feed based on their interests.

Leetcode 23. Merge k Sorted Lists

Leetcode 62. Unique Paths

Count the number of distinct monotonic paths from the top-left to the bottom-right of an m×n grid when you may only move right or down. This is the classic lattice-path problem — the answer equals binomial coefficient C(m+n-2, m-1) (or can be computed with DP); m,n ≤ 100 and result ≤ 2·10^9.

Design Facebook Live Comments

Design a real-time commenting system that allows users to view and post comments instantly while watching live videos or browsing posts across Meta platforms. The system should handle Facebook-scale traffic (~2B DAU) and support features like reactions, live notifications, and seamless user transitions between different content.