Infosys Specialist Programmer L3 Interview Experience
Summary
I cleared the Infosys Specialist Programmer L3 interview, passing the online assessment and on‑site interview, and was selected for the role.
Full Experience
Company: Infosys Role: Specialist Programmer L3 Years of Experience : 0 (Fresher) Mode: Oncampus College: Tier 3 Year of Graduation: 2026
Infosys came to my college oncampus for hiring of DSE / SP L1,L2,L3 roles
Round 1 : Online Assessment (Offline Round): January 19, 2026
Online assessment questions:
-
Based on prime factorization and optimization Q) find max sum subarray with conditions like prime factors of product should be m , bitwise & should be <=x , and few conditions - I precomputed prime factors and solved it (12/12 Testcases)
-
2d dp similar to LIS but with different conditions Q ) maximum number of gates u can take based on some conditions of 2 arrays - used LIS type of dp (12/12 Testcases)
-
bfs + matrix + geometry Q ) transaction states , 2d points , centroid , some formulas , find the sequence with highest score (12/12 Testcases)
-
tree+ dp + backtracking + bitwise - Q) tree , take par and child get some score , if all bits r taken some score , if few are taken some score , etc, take m nodes and maximise score (6/12 Testcases)
I solved 3 full and 4th question 6/12 testcases Got shortlisted for Specialist Programmer L3 Interview Results were announced on January 20, 2026
Round 2: Interview (January 21, 2026 - Infosys Office Offline)
DSA Questions -
- Given some coins , use minimum no of coins (you may pick one coin infinite times) to sum up to the target sum.(Medium) Interviewer asked me explain approach and solve it on pen paper
- given 2 sorted arrays , let n = size of first array , m = size of 2nd array , re arrange the elements in such a way that the elements in array1 are all lesser than elements in array 2 , and both array 1 and array 2 is sorted (Don't use inbuilt sort functions or extra space)(Hard) Interviewer asked me to code this on notepad
- Given a sentence , sort the words in them based on their size and if size is same , sort them based on their lexicographical order.(Easy) Interviewer asked me to code this in online compiler
Questions:
- CAP Theorem
- How does SQL and Redis follow CAP Theorem
- Fragmentation in OS and types
- Design patterns - Singleton , Factory , etc
- SQL vs No SQL
- Uber ER Diagram and system design discussion
- Deep dive in my project, APIs used , authentication method and the interviewer asked me to draw the system architecture of it.
- SQL Query to print first_name , middle_name , last_name combined as full_name , but middle and lastname may have NULL Values.
- Discussion on ranks in Coding contests and achievements
- Stack vs Heap memory in C++
- Discussion on current internship
Verdict : Selected for Specialist Programmer L2
Some Tips:
- Focus on CP Style / Leetcode Hard for OA Round (DP,Graph,Greedy) - For context I am Guardian in Leetcode & Expert on Codeforces , So I naturally felt more comfortable in OA and interview DSA questions.
- Focus on AI, DSA, System Design, Core CS for Interview Round
- Emphasize more on AI/ML Projects if you have
- Be Confident
Interview Questions (14)
Minimum Coin Change (Unlimited Coins)
Given a set of coin denominations, find the minimum number of coins needed (you may use each coin an unlimited number of times) to reach a target sum.
In‑place Merge of Two Sorted Arrays
Given two sorted arrays where the first has size n and the second has size m, rearrange the elements in such a way that all elements in array1 are less than all elements in array2, and both arrays remain sorted. Do not use built‑in sort functions or any extra space.
Sort Words by Length and Lexicographical Order
Given a sentence, sort its words based on their length. If two words have the same length, sort them lexicographically.
CAP Theorem
Explain the CAP theorem and its implications for distributed systems.
SQL and Redis and CAP Theorem
Describe how SQL databases and Redis relate to the CAP theorem.
Fragmentation in Operating Systems
Discuss fragmentation in operating systems and the different types of fragmentation.
Design Patterns: Singleton and Factory
Explain the Singleton and Factory design patterns, including their use cases and advantages.
SQL vs NoSQL
Compare relational (SQL) databases with NoSQL databases, covering key differences and use‑cases.
Uber ER Diagram and System Design Discussion
Discuss a high‑level ER diagram and system design for a ride‑sharing service similar to Uber.
Project Deep‑Dive and Architecture Diagram
Provide a detailed walkthrough of my project, covering the APIs used, authentication methods, and draw the overall system architecture.
SQL Query to Concatenate Full Name Handling NULLs
Write an SQL query that returns a column full_name by concatenating first_name, middle_name, and last_name, where middle_name and last_name may be NULL.
Stack vs Heap Memory in C++
Explain the differences between stack and heap memory allocation in C++, including when each is used and their performance characteristics.
Discussion on Coding Contest Ranks and Achievements
Talk about my rankings in competitive programming contests and any notable achievements.
Discussion on Current Internship
Describe my current internship responsibilities, projects, and technologies used.
Preparation Tips
- Focus on CP style / LeetCode Hard problems for the online assessment (DP, Graph, Greedy).
- Strengthen AI, DSA, System Design, and core CS fundamentals for the interview round.
- Highlight AI/ML projects if you have them.
- Be confident.