7
Questions
2–4 weeks
Process Length
Medium-Hard
Difficulty
X (formerly Twitter) is a real-time social platform serving hundreds of millions of users. After significant restructuring, X now operates as a leaner, faster-moving company. Interviews focus heavily on distributed systems, real-time data processing, and the ability to work in a high-velocity environment with minimal bureaucracy.
Q1: Design a trending topics algorithm that identifies popular hashtags in real-time.
Q2: Implement a tweet timeline service that returns the most recent tweets from followed users.
Q3: Build a URL shortener with analytics tracking (click counts, geographic distribution).
Q1: Design Twitter's real-time tweet delivery system at scale.
Q2: Design a content moderation system that handles millions of tweets per day.
Q1: How do you handle working in a fast-changing, uncertain environment?
Q2: Tell me about a time you shipped something significant with a very small team.
X offers unique opportunities to work on real-time systems at massive scale with a small, high-impact team. The environment is fast-paced and less bureaucratic than larger companies. However, the company has undergone significant changes since the acquisition, so research current employee reviews before deciding.
X primarily uses Scala, Java, and Python for backend services. Key infrastructure includes Apache Mesos (now migrating to Kubernetes), Manhattan (custom distributed database), and a custom RPC framework. Frontend uses React and GraphQL.
The interview process has become faster and more streamlined. There are typically fewer rounds (3–4 vs the previous 5–6), decisions are made more quickly, and there's greater emphasis on practical skills and execution speed. The technical bar remains high, but cultural fit questions have shifted toward adaptability and pace.