Infosys Specialist Programmer (L3) Interview Experience

I recently interviewed for Infosys Specialist Programmer (L3), so sharing my experience in case it helps others preparing.

Process

The process had 2 stages:

Online Assessment → Final Interview

My OA score got me directly mapped to L3. Others were mapped to L1/L2/DSE based on performance.

Round 1 — Online Assessment (OA)

The OA was mostly focused on graph problems, with difficulty around LeetCode Medium → Hard.

Round 2 — Final Interview

The final interview was heavily focused on DSA, System Design / Architecture, and CS Fundamentals.

DSA

I was asked:

• One sliding window question

• One linked list question

System Design / Architecture — Main Focus

This was the main focus of the interview.

The major question was:

“Design Twitter from scratch.”

The discussion then went into how to scale the system from:

10 → 100 → 1k → 10k → 1M+ users

The discussion went deep into:

• Architecture

• Tradeoffs

• Components

• Scaling strategy

It wasn't just about knowing definitions — they wanted to understand how I would actually structure and scale the system.

CS Fundamentals

The interview also covered:

• OOP

• DBMS

• Computer Networks

Overall Experience

Overall, the interview was very architecture- and system-design heavy.

They cared more about clarity, reasoning, and how you structure a system rather than definitions or memorized answers.