Twitter / X
Real-time social platform with petabyte-scale data and ML ranking systems.
4 Rounds
~14 Days
Hard
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Full Stack Engineer
•
Behavioral
•
hard
What is the most complex system you have built from scratch, and what were the key technical trade-offs you had to make?
#Architecture
#Trade-offs
#End-to-End Ownership
Full Stack Engineer
•
System Design
•
hard
Design a real-time Direct Messaging (DM) system for X, supporting 1-on-1 and group chats with read receipts.
#WebSockets
#NoSQL
#Real-time
#Pub/Sub
Full Stack Engineer
•
System Design
•
hard
Design the X Home Timeline. How do you ensure sub-second latency for users with millions of followers?
#Fanout
#Caching
#Message Queues
#Database Sharding
Full Stack Engineer
•
System Design
•
hard
Design X's Trending Topics system. How do you calculate trends in real-time across different geographic regions?
#Stream Processing
#Apache Kafka
#Count-Min Sketch
#Distributed Systems
Full Stack Engineer
•
System Design
•
hard
Design the Like and Retweet counter system. How do you handle the massive write load when a tweet goes viral?
#Eventual Consistency
#Batching
#Distributed Counters
Full Stack Engineer
•
System Design
•
hard
Design a video upload and processing pipeline for X. Users can upload up to 2 hours of 1080p video.
#Blob Storage
#Asynchronous Processing
#CDN
#Video Encoding
Full Stack Engineer
•
System Design
•
medium
Design X's push notification system. How do you ensure notifications are delivered reliably and not duplicated?
#Message Queues
#APNs/FCM
#Idempotency
Full Stack Engineer
•
System Design
•
medium
Design a search system to find specific tweets by a user within a specific date range.
#Elasticsearch
#Inverted Index
#Data Partitioning
Full Stack Engineer
•
System Design
•
hard
Design the architecture for X Spaces (live audio rooms). How do you handle thousands of listeners and multiple speakers with low latency?
#WebRTC
#Audio Streaming
#SFU
#Scalability
Full Stack Engineer
•
System Design
•
hard
Design an ad-serving system for the X feed. How do you select the most relevant ad in under 50ms?
#Machine Learning Inference
#Low Latency
#Auction Algorithms
Full Stack Engineer
•
System Design
•
hard
Design a system to detect and filter out spam or bot replies in real-time before they are rendered to users.
#Machine Learning
#Stream Processing
#Rules Engine
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.