Amazon Interview Experience – Online Assessment to System Design

Landing an interview with Amazon is exciting, but also challenging. The process is structured to test not only your DSA (Data Structures & Algorithms) skills but also your ability to adapt to real-world problems, apply leadership principles and design scalable systems. Below is my complete interview experience with Amazon, broken down round by round.

Round 1: Online Assessment (Medium Level)

• Duration: 60 minutes
• Mode: Remote
• Coding Problems: 2

The online assessment began with two DSA problems that went smoothly.

Problems Asked:

1. Valid Parenthesis Checker
   Classic stack-based problem to validate balanced parentheses.

2. Longest Substring Without Repeating Characters
   A sliding window problem requiring careful handling of indices and hash maps.

Work Simulation Round:

• Managed multiple emails.
• Diagnosed issues like a product page not loading.
• Took quick decisions while prioritizing tasks.

Behavioral Questions:

• Multiple-choice behavioral scenarios, where I had to choose the most likely and least likely responses in workplace situations.

Finally, I received an email asking me to fill out a survey before moving on to the next stage.

Round 2: DSA – Graph Problem (Medium Level)

• Duration: 60 minutes
• Mode: Remote
• Coding Problems: 1

This round focused on a graph-based problem.

Problem Asked:

1. Evaluate Division Variation
   Read input, build a graph and output results accordingly.
   Approach: Graph traversal (DFS/BFS).

Round 3: DSA (Easy Level)

• Duration: 60 minutes
• Mode: Remote
• Coding Problems: 1

Problem Asked:

1. Maximum Size Subarray Sum Equals k
   A subarray sum problem solvable using prefix sum + hash map.

This one was relatively easy and I solved it quickly. Soon after, I got a call to schedule the next round on the same day.

Round 4: System Design (Hard Level)

• Duration: 60 minutes
• Mode: Remote

This was the most challenging round.

Task:

Design a bookstore system with multiple books and the ability to return the count of a particular word (e.g. a fictional character) from a specific book.

My Approach:

• Defined classes, objects and methods clearly.
• Discussed how to efficiently store and search for words (indexing, hash maps and search optimizations).
• Structured my solution logically with scalability in mind.

The interviewer was happy with my explanation and asked follow-up questions about my past projects, contributions and impact.

Round 5: DSA + Tech Stack Discussion (Medium Level)

• Duration: 60 minutes
• Mode: Remote

This round started with a deep dive into my current work and tech stack discussions (around 40 minutes). The interviewer asked about:

• My role in projects.
• Challenges faced and how I solved them.
• Technical decisions and trade-offs.

DSA Problem Asked:

Since time was left, I was given another medium-level sliding window problem:

1. Maximum Size Subarray Sum Equals k
   Similar to Round 3.

My Final Thoughts

The Amazon interview process is designed to test you on:

• DSA mastery (arrays, strings, graphs, sliding window, prefix sums).
• Problem-solving in real-world scenarios through simulations.
• System design skills for scalability and efficiency.
• Behavioral alignment with Amazon’s Leadership Principles.

If you’re preparing, focus on:

1. Practicing LeetCode Medium/Hard problems.
2. Strengthening system design fundamentals.
3. Revisiting Amazon Leadership Principles and applying them in answers.