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X's Interview Process (2026)

Blog / X's Interview Process (2026)

X's software engineer interview process is known for moving fast and cutting straight to technical depth. Most candidates report a streamlined pipeline that typically spans 3 to 5 stages, though the exact structure can vary by team and role level.

Recruiter Screen: Usually a 30 to 45 minute call covering your most technical projects, language proficiency, and general fit for X's high-intensity culture. Recruiters often ask for a concise summary of a past project, so be ready to communicate impact quickly.
Technical Assessment: Depending on the team, this is typically a 60 to 90 minute automated coding challenge or a longer real-world scenario, sometimes up to a few hours, designed around problems relevant to X's platform.
Technical Phone Screen: A live coding session with an engineer, usually around 45 to 60 minutes. Interviewers often introduce ambiguity intentionally, so they are watching how you think and communicate as much as whether you reach the right answer.
Onsite or Virtual Loop: Generally 3 to 6 rounds covering deep technical coding, system design, and behavioral interviews. System design tends to be the most heavily weighted round for mid-level and senior candidates.

To prepare effectively, focus your study across these key areas that consistently show up in X's SWE interviews:

Data Structures & Algorithms (DSA): Practical coding problems focused on real-world implementation over abstract puzzles.
System Design (High-Level Design): Designing large-scale X platform features with a focus on latency, reliability, and scale.
Low-Level Design: Object-oriented design and implementation of thread-safe, production-ready components.
API Design: Designing clean, scalable APIs for real-time and high-throughput X platform features.
Behavioral: Ownership, adaptability, and high-pressure decision-making in X's engineering culture.

1. Data Structures & Algorithms (DSA)X has moved away from trick-based brain teasers toward what engineers internally call 'Tuesday Coding' - the kind of problems you'd actually solve on the job. Expect practical questions like implementing an Design LRU Cache, a hit counter, or a Task Scheduler with Cooldown Period.Concurrency is a recurring theme. You may be asked to implement thread-safe data structures or reason about race conditions in a distributed environment, so make sure your fundamentals around locks and synchronization are solid.Grid and tree problems also appear regularly. Word Search II, which combines a Trie with DFS, is a strong example of the type of problem X favors. Brush up on tries and graphs as part of your prep.For a broad foundation, work through our top 100 DSA questions to make sure you have the most commonly tested patterns covered before your screen.

2. System Design (High-Level Design)System design is the most critical round for mid-level and senior roles at X. You are expected to reason about latency, reliability, and scale at millions of requests per second, not just sketch boxes on a whiteboard.Expect X-specific prompts like designing the News Feed (Twitter, X), a Notification System, or real-time search across billions of tweets. Interviewers want to see you reason through trade-offs, not just recite a standard architecture.AI-integrated design questions are also emerging. Some teams ask you to design a recommendation service that uses an LLM to re-rank results while managing inference cost and latency, so factor that into your prep.Practice drawing out full architectures using our System Design Whiteboard and review core concepts on our High-Level Design topic page.

3. Low-Level DesignX's low-level design rounds focus on building production-ready components, not just defining class diagrams. You may be asked to implement something like a Message Processing System or a thread-safe task executor from scratch.Rate limiting comes up frequently, both as a standalone problem and embedded in larger designs. Working through a Thread-Safe Rate Limiter end-to-end is solid practice for what you might face.The emphasis is on clean, testable code. Candidates who write test cases before or alongside their implementation tend to score significantly higher on production-readiness signals. Head to our Low-Level Design practice section to get reps in on these types of problems.

4. API DesignAPI design rounds at X tend to focus on high-throughput, real-time scenarios directly tied to the platform. Expect prompts like designing the Design Twitter Home Timeline (News Feed) API or a Design a Real-time Notification System that can fan out to millions of users.You should be comfortable discussing the trade-offs between REST and RPC, and when to reach for each. Interviewers at X are particularly interested in how your API handles load, versioning, and failure modes at scale.Rate limiting is a common component in these discussions. Practicing the Rate Limiter system design will help you speak confidently about throttling strategies when they come up in the API design context.

5. BehavioralX's behavioral rounds are focused on ownership and operating well under pressure. Common questions include things like 'Tell me about a time you solved something others thought was impossible' or 'How do you handle a production failure with incomplete information.'The culture values people who take end-to-end responsibility for a problem, so frame your answers around the full arc: what was broken, what you did, and what the outcome was. Vague or committee-style answers tend to land flat here.Structure your responses using the STAR principle to keep your answers tight and specific. For broader prep, the Behavioral Interview Course covers the patterns that matter most for high-ownership engineering cultures like X's.

ConclusionX moves fast, and your prep should match that pace. Focus on practical coding, scalable system design, and behavioral answers that show real ownership. Follow the X Interview Roadmap for a structured, step-by-step plan that covers every stage of the process.