Twitter (X) Placement Papers 2025

Overview

This page is a working set of Twitter (X) placement papers from 2025: from student reports questions, the 2025 online assessment pattern, and step-by-step solutions. Use it to see what Twitter (X) actually asked in the latest cycle, how hard the rounds were, and which themes (DSA, system design, aptitude, or role-specific topics) mattered most. Practice the problems below under timed conditions, then cross-check with the interview and preparation guides if you are targeting an upcoming Twitter (X) drive.

2025 Updates

The 2025 Twitter placement process maintains focus on DSA and system design with enhanced emphasis on real-time systems.

Twitter Online Assessment 2025 pattern

Section	Questions	Time	Difficulty
Coding Problems	2-3	90 min	Medium-Hard

X Placement Papers 2025 - actual questions & solutions

This section contains practice questions styled on X (Twitter) placement papers 2025 (recent-cycle pattern), with worked solutions. Use them as timed sectional drills - from student reports drives vary by college and role, so treat this as a high-signal practice bank, not an official paper dump.

Question 1: maximum subarray sum

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Problem Statement: Find the contiguous subarray with the largest sum.

Example:

Input: [-2, 1, -3, 4, -1, 2, 1, -5, 4]
Output: 6  // [4, -1, 2, 1]

Solution (Java):

public int maxSubArray(int[] nums) {
    int best = nums[0], cur = nums[0];
    for (int i = 1; i < nums.length; i++) {
        cur = Math.max(nums[i], cur + nums[i]);
        best = Math.max(best, cur);
    }
    return best;
}

Time Complexity: O(n)
Space Complexity: O(1)

Question 2: longest common prefix

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Problem Statement: Find the longest common prefix string amongst an array of strings.

Example:

Input: ["flower","flow","flight"]
Output: "fl"

Solution (Java):

public String longestCommonPrefix(String[] strs) {
    if (strs.length == 0) return "";
    String pref = strs[0];
    for (int i = 1; i < strs.length; i++) {
        while (!strs[i].startsWith(pref)) {
            pref = pref.substring(0, pref.length() - 1);
            if (pref.isEmpty()) return "";
        }
    }
    return pref;
}

Time Complexity: O(S)
Space Complexity: O(1)

Question 3: binary tree level order

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Problem Statement: Return the level-order traversal of a binary tree.

Example:

Input: [3,9,20,null,null,15,7]
Output: [[3],[9,20],[15,7]]

Solution (Java):

public List<List<Integer>> levelOrder(TreeNode root) {
    List<List<Integer>> res = new ArrayList<>();
    if (root == null) return res;
    Queue<TreeNode> q = new ArrayDeque<>();
    q.add(root);
    while (!q.isEmpty()) {
        int sz = q.size();
        List<Integer> level = new ArrayList<>();
        for (int i = 0; i < sz; i++) {
            TreeNode n = q.poll();
            level.add(n.val);
            if (n.left != null) q.add(n.left);
            if (n.right != null) q.add(n.right);
        }
        res.add(level);
    }
    return res;
}

Time Complexity: O(n)
Space Complexity: O(n)

Question 4: rotate array right by k

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Problem Statement: Rotate the array to the right by k steps.

Example:

Input: [1,2,3,4,5,6,7], k = 3
Output: [5,6,7,1,2,3,4]

Solution (Java):

public void rotate(int[] nums, int k) {
    k %= nums.length;
    reverse(nums, 0, nums.length - 1);
    reverse(nums, 0, k - 1);
    reverse(nums, k, nums.length - 1);
}
void reverse(int[] a, int l, int r) {
    while (l < r) { int t = a[l]; a[l++] = a[r]; a[r--] = t; }
}

Time Complexity: O(n)
Space Complexity: O(1)

Question 5: detect cycle in linked list

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Problem Statement: Return true if the linked list has a cycle.

Example:

Input: 3→2→0→-4→(back to 2)
Output: true

Solution (Java):

public boolean hasCycle(ListNode head) {
    ListNode slow = head, fast = head;
    while (fast != null && fast.next != null) {
        slow = slow.next;
        fast = fast.next.next;
        if (slow == fast) return true;
    }
    return false;
}

Time Complexity: O(n)
Space Complexity: O(1)

Question 6: two sum

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Problem Statement: Given an array of integers and a target, return indices of two numbers that add up to target.

Example:

Input: nums = [2, 7, 11, 15], target = 9
Output: [0, 1]

Solution (Java):

public int[] twoSum(int[] nums, int target) {
    Map<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        int need = target - nums[i];
        if (map.containsKey(need)) return new int[]{map.get(need), i};
        map.put(nums[i], i);
    }
    return new int[]{};
}

Time Complexity: O(n)
Space Complexity: O(n)

Question 7: climbing stairs

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Problem Statement: You can climb 1 or 2 steps. How many distinct ways to climb n stairs?

Example:

Input: n = 4
Output: 5

Solution (Java):

public int climbStairs(int n) {
    if (n <= 2) return n;
    int a = 1, b = 2;
    for (int i = 3; i <= n; i++) {
        int c = a + b; a = b; b = c;
    }
    return b;
}

Time Complexity: O(n)
Space Complexity: O(1)

Question 8

Q8: Which SQL clause filters grouped rows after GROUP BY?

Solution:

HAVING filters aggregates; WHERE filters rows before grouping.

Answer: HAVING

Question 9

Q9: Worst-case time complexity of quicksort is?

Solution:

Unbalanced partitions (already sorted with bad pivot) → O(n²).

Answer: O(n²)

Question 10

Q10: Time complexity of binary search on a sorted array of n elements is?

Solution:

Each step halves the search space → O(log n).

Answer: O(log n)

Question 11

Q11: Which protocol is connection-oriented at the transport layer?

Solution:

TCP is connection-oriented; UDP is connectionless.

Answer: TCP

Key insights from 2025 twitter Online Assessment

1. Coding Section is Critical: Must solve 2-3 coding problems correctly to advance
2. Real-Time System Design: Strong emphasis on real-time systems and feed generation
3. Time Management: 2-3 coding problems in 90 minutes requires excellent speed
4. Success Rate: Only 10-15% cleared OA and advanced to interviews
5. Platform: Twitter’s assessment platform or HackerRank
6. Focus Areas: Arrays, trees, graphs, dynamic programming, real-time systems, feed algorithms
7. Enhanced Emphasis: Optimal solutions and AI-powered features

Twitter 2025 interview experiences

Based on recent candidate experiences from 2025 Twitter (X) interviews:

2025 Interview Process:

1. Online Assessment (90 minutes): 2-3 coding problems
2. Technical Phone Screen (45-60 minutes): Coding problems, algorithm discussions, system design, AI features
3. Onsite/Virtual Interviews (4-5 rounds, 45-60 minutes each):

• Coding rounds (2-3): Algorithms, data structures, problem-solving
• System Design rounds: Real-time feed systems, social media platforms, AI-powered features, scalability
• Behavioral rounds: Problem-solving approach, innovation, teamwork, impact

2025 Interview Trends:

• Increased emphasis on AI-powered features and real-time systems
• More focus on optimal solutions and system design
• Enhanced behavioral questions about innovation and impact
• Questions about Twitter’s AI features and real-time processing

Common 2025 Interview Topics:

• Coding: Arrays, strings, trees, graphs, dynamic programming, feed generation algorithms
• System Design: Real-time feed systems, social media platforms, AI-powered features, scalability
• Behavioral: Problem-solving, innovation, teamwork, impact, AI/ML passion
• Twitter Technologies: Feed generation, real-time systems, AI features, social media algorithms

Success Tips:

• Strong coding performance is essential - solve problems optimally
• Practice system design for real-time systems and AI-powered social media platforms
• Prepare examples demonstrating innovation and problem-solving
• Learn Twitter’s products, AI features, and real-time systems
• Practice explaining your thought process clearly

For detailed interview experiences from 2025, visit Twitter Interview Experience page.

Preparation tips for twitter 2025 pattern

1. Master Coding Fundamentals: Focus on solving 2-3 coding problems correctly - arrays, trees, graphs, DP
2. System Design Mastery: Learn real-time system design, feed generation, AI-powered social media platforms
3. Practice Previous Year Papers: Solve Twitter OA papers from 2020-2025 to understand evolving patterns
4. Time Management: Practice completing 2-3 coding problems in 90 minutes
5. LeetCode Practice: Solve 200+ LeetCode problems focusing on arrays, strings, trees, graphs (medium-hard difficulty)
6. Real-Time Systems: Understand real-time feed generation, social media algorithms, AI features, scalability
7. Twitter Technologies: Learn feed generation, trending topics, AI-powered features, real-time systems
8. Behavioral Preparation: Prepare examples using STAR format - innovation, problem-solving, impact
9. Mock Tests: Take timed practice tests to improve speed and accuracy
10. Distributed Systems: Understand distributed systems, scalability, and real-time processing
11. AI/ML Basics: Understand AI/ML fundamentals and applications in social media

Comments & Suggestions

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