HackerRank SDE-2 | Interview Experience | ✅ Selected
Summary
I interviewed for a Senior Software Engineer (SDE-2) role at HackerRank, which involved an online assessment, DSA, LLD, HLD, and managerial rounds, and I was ultimately selected.
Full Experience
Hello Community,
Recently, I interviewed for the Senior Software Engineer (SDE-2) role at HackerRank. I have 4 years 3 months of experience, currently working as a Software Development Engineer in a product-based organization. I applied via LinkedIn.
Below is my interview experience.
🧪 Online Coding Assessment (HackerRank Platform)
Duration: ~75 minutes
Format: Questions unlocked sequentially
Question: Binary array problem involving prefix balance and optimal subarray length. ✔ Solved using prefix-sum + hashmap.
Follow-up: Allowed a limited modification in the array to maximize the result. ✔ Solved using sliding window.
Second Follow-up: More constraint-heavy variant focusing on prefix validity. ➖ Partial solution, but approach and reasoning were discussed.
👨💻 Code Pairing – DSA Round
Duration: 1 hour
Platform: Shared HackerRank editor
Question 1: Log-processing problem to detect suspicious users based on transaction frequency. ✔ Solved using maps and clean edge-case handling.
Question 2: Binary / string manipulation problem with tight constraints. ✔ Solved with iterative optimization and discussion.
Strong focus on clarity of thought and communication.
🧩 Low Level Design (LLD) Round
Duration: ~60 minutes
Problem: Design a rate-limiting / notification-style system (API + core classes).
Discussion included:
Identifying entities and relationships
Class design and responsibilities
Hovering concurrency and edge cases
Extensibility and trade-offs
Interviewer focused on design thinking and practical choices, not UML perfection.
🧠 High-Level System Design Round
Duration: 1 hour
Tool: Diagram-based interface
Problem: Design an online coding assessment platform (similar to HackerRank).
Covered:
Functional & non-functional requirements
High-level architecture
Core services and data models
Code submission & evaluation flow
Scalability and trade-offs
Very collaborative and discussion-driven.
🧑💼 Managerial Round
Focused on:
Past project ownership
Decision-making and trade-offs
Collaboration and growth mindset
More conversational than technical.
🤝 HR Discussion
Compensation and role expectations
Hybrid setup (3 days WFO – Bengaluru)
Team fit and long-term growth
✅ Verdict: Selected
Overall, a well-structured and engineering-focused process with balanced emphasis on DSA, design, and real-world problem solving.
Hope this helps others preparing for HackerRank interviews. Happy to answer general questions 🙂
Interview Questions (7)
Binary Array with Prefix Balance and Optimal Subarray
Binary array problem involving prefix balance and optimal subarray length.
Binary Array with Limited Modification
Allowed a limited modification in the array to maximize the result.
Binary Array with Prefix Validity Constraints
More constraint-heavy variant focusing on prefix validity.
Log Processing for Suspicious Users
Log-processing problem to detect suspicious users based on transaction frequency.
Binary/String Manipulation with Tight Constraints
Binary / string manipulation problem with tight constraints.
Design a Rate Limiting / Notification System
Design a rate-limiting / notification-style system (API + core classes).
Discussion included:
Identifying entities and relationships
Class design and responsibilities
Hovering concurrency and edge cases
Extensibility and trade-offs
Interviewer focused on design thinking and practical choices, not UML perfection.
Design an Online Coding Assessment Platform
Design an online coding assessment platform (similar to HackerRank).
Covered:
Functional & non-functional requirements
High-level architecture
Core services and data models
Code submission & evaluation flow
Scalability and trade-offs
Very collaborative and discussion-driven.