System Design Interview Prep:
A Beginner's Roadmap

Master core concepts, components, and strategies to crack your next interview with confidence.

Introduction

When individuals hear about getting hired at top tech companies such as Amazon, the image that comes into their minds is of computer science graduates from top universities. But here’s reality: there is no need to have a CS degree to be employed by Amazon or any top tech firm.

Actually, most of the professionals from mechanical engineering, civil engineering, electrical engineering, mathematics, physics, and non-technical streams have succeeded in solving the Amazon interview process. It’s not about what degree you have, but rather skill, problem-solving skills, and determination.

In this blog, we’ll walk through the inspiring journey of a non-CS student who got into Amazon, the challenges faced, the strategies used to prepare, and lessons for anyone aiming to break into top tech companies.

The Background: Starting Without a CS Degree

Let us start with a Mechanical Engineering student. Similar to most non-CS students, the aspiration to work in a top product-based firm was far-off. With less computer science exposure in college, programming was like a different world.

The shared problems on hand were:

Less scope for programming in the syllabus.
No less guidance on DSA (Data Structures and Algorithms).
Fear of competing with CS students with years of head start.
Self-doubt as to whether Amazon and other such companies would even look at non-CS candidates.

But what this student understood was that Amazon and other such companies value problem-solving abilities over your degree. The moment this mental shift occurred, the actual journey started.

Step 1: Building the Foundation

Without a CS degree, the initial step was to start building programming fundamentals from zero. This involved:

Learning C++/Java/Python to become familiar with code syntax.
Learning the fundamentals of time and space complexity.
Solving easy problems on sites such as HackerRank and LeetCode.

Rather than diving directly into complex concepts, the student spent the initial months simply becoming familiar with simple loops, arrays, strings, and recursion.

Step 2: Learning Data Structures and Algorithms (DSA)

The actual secret to acing Amazon interviews is mastery of DSA. Having a non-CS background, this was the most challenging one. The student constructed a study plan:

Arrays and Strings – problem mastery on searching, sorting, sliding window.
Linked Lists – mastery of pointers, reverse linked list, cycle detection.
Stacks and Queues – problem-solving on parentheses, min/max stack.
Trees and Graphs – mastery of traversals, BFS, DFS, shortest path algorithms.
Dynamic Programming – practicing traditional DP problems such as knapsack, LIS, coin change.
Consistency was the key. Practicing 3–5 problems a day slowly built confidence.

Step 3: Practice using Online Sites

The student practiced coding problems on several sites:

LeetCode – for Amazon-labeled problems (most interview questions are going to look similar).
GeeksforGeeks – for theory and everyday questions.
Codeforces/CodeChef – for competitive programming and increasing speed.
InterviewBit – for mock interview-style practice.

By completing 200+ problems, the student learned to become very proficient at problem-solving, which is precisely what Amazon assesses during interviews.

Step 4: System Design & Core Concepts

For Amazon’s advanced-level interviews, system design and computer science concepts come into play. As the student lacked formal CS education, additional effort was required to fill in:

Operating Systems (OS) concepts such as processes, threads, and deadlocks.
Database Management Systems (DBMS) – SQL queries, normalization, indexing.
System Design – concepts of scalability, caching, and load balancing.
Materials such as YouTube tutorials, GeeksforGeeks blog posts, and free system design tutorials bridged the knowledge gap.

Step 5: The Application Process

Most non-CS students are afraid to apply, assuming that their degree will be a hindrance. But Amazon’s application process is available to all streams, provided you possess the right skills.

This student applied through:

Amazon’s Careers Portal.
On-campus/off-campus drives.
Employee referrals (a strong method of getting noticed).

Having a good resume with projects, internships, and coding profiles assisted in standing out.

Step 6: Amazon Interview Experience

Amazon interview process generally consists of these rounds:

Online Assessment (OA)
Two coding questions on DSA.
Debugging and logical thinking.
Technical Interviews (2–3 rounds)
Array, string, linked list, tree, graph, DP questions.
Some CS basics like DBMS and OS basics.
Managerial/Bar Raiser Round
Emphasis on Amazon’s Leadership Principles.
Behavioral questions such as “Tell me about a time you have failed and how you dealt with it.”

Even though he wasn’t from a CS background, the student did well due to regular practice and a clear grasp of Amazon’s values.

Conclusion

This tale of a non-CS major breaking into Amazon shows that everyone has the potential to become part of top tech companies with the right approach. It has nothing to do with what degree you have, but rather how prepared, practiced, and aligned you are with the values of the company.

If you’re a non-CS student aspiring for Amazon, don’t let fear limit you. Begin small, be consistent, and work on DSA + projects + behavioral preparation. With dedication, your story can be the next success story.

Here at Coding with IITians, we’ve witnessed numerous non-CS students change their lives and secure jobs at FAANG companies. Keep in mind that your background is not a constraint—it’s merely the beginning of your journey.