ServiceNow Software Engineer Intern Interview Experience (2 Rounds)

• Company: ServiceNow
• Role: Software Engineer Intern
• Experience Level: Fresher
• Interview Mode: Remote
• Difficulty Level: Medium
• Interview Timeline: 1–2 Weeks
• Result: Rejected
• Total Rounds: 2

Round 1 (Online Assessment)

• Duration: 60 Minutes
• Difficulty: Medium

The first round consisted of three coding problems.

• The first problem was based on Arrays and was relatively straightforward.
• The second problem focused on Trees, covering standard tree concepts and traversal techniques.
• The third problem was significantly more difficult and resembled a classic hard-level DSA problem.

Overall, the assessment tested problem-solving ability across multiple data structures with increasing difficulty.

Round 2 (Technical Interview)

• Duration: 60 Minutes
• Difficulty: Medium

The interview began with a friendly discussion about my background, projects and interests. The interviewer asked me to introduce myself, explain where I grew up, discuss my favorite programming languages and share why I enjoy software development. I kept my introduction concise while highlighting my passion for building applications from scratch.

AVL Tree Discussion

The interviewer asked several conceptual questions about AVL Trees. Topics discussed included:

• What makes an AVL Tree different from a standard Binary Search Tree?
• Why AVL Trees remain balanced.
• Different types of tree rotations.
• How single and double rotations work.
• Time complexity of search, insertion and deletion.
• Advantages of AVL Trees over regular BSTs.

The interviewer also asked about real-world applications. I mentioned:

• Database indexing
• File systems
• Situations where consistently balanced search performance is important

Linked List Coding Problem

The main coding question involved reversing multiple sections of a linked list.

Problem

Reverse:

• the first k nodes,
• followed by the next m nodes,

while maintaining the remaining structure of the linked list.

My Approach

I explained my approach before writing the code. My solution included:

• Using a dummy node
• Iterative traversal
• In-place reversal
• Proper reconnection of the reversed segments

After completing the implementation, the interviewer tested the solution with several edge cases. Some of them included:

• Empty linked list
• Single node
• k greater than the list length
• Small list sizes

Estimation / Math Puzzle

The final question was a classic estimation puzzle.

• Estimate how many golf balls can fit inside a bus.

The interviewer was more interested in the reasoning process than the exact answer. I broke the problem into multiple assumptions:

• Estimated the dimensions of a bus
• Estimated usable internal volume
• Estimated the size of a golf ball
• Considered packing efficiency
• Calculated an approximate final value

The key was to explain every assumption logically.

Interview Questions

1. Reverse multiple segments of a Linked List.
2. AVL Tree concepts and rotations.
3. Estimation puzzle (Golf balls inside a bus).

Overall Experience

The interview experience was positive and well structured. The interviewer was friendly and focused on understanding both conceptual knowledge and coding ability rather than simply checking whether the final answer was correct.

The discussion covered data structures, coding and analytical thinking through an estimation problem.

Preparation Tips

From my experience:

• Strengthen your Data Structures and Algorithms fundamentals.
• Practice Linked List problems extensively.
• Revise Trees, especially AVL Trees and balancing operations.
• Be comfortable explaining your thought process while coding.
• Practice estimation and logical reasoning questions.
• Prepare for edge cases before finalizing your solution.

My Advice

If you're preparing for a ServiceNow Software Engineer Intern interview:

• Focus heavily on DSA.
• Practice medium and hard-level coding questions.
• Revise tree balancing concepts thoroughly.
• Communicate your approach clearly before writing code.
• Stay calm during estimation questions and explain every assumption logically.

Good communication combined with solid problem-solving skills can make a significant difference during the interview.