Infosys Technical Interview Questions 2026

The Infosys technical interview is where the three hiring tracks diverge: the same core topics (OOP, DBMS, OS, DSA) get probed at very different depths depending on whether you are sitting the SE, SP or PP interview.

Three Tracks, Three Interview Depths

Infosys hires freshers across three compensation bands, each with its own technical interview profile:

Track	Starting CTC	Technical interview focus
System Engineer (SE)	₹3.6 LPA	OOP fundamentals, DBMS, OS basics, one coding question
Specialist Programmer (SP)	₹6.5 LPA	DSA, algorithms, complexity, OOP in depth, live coding
Power Programmer (PP)	₹9.5 LPA	Advanced DSA, system design concepts, stronger coding section

SE is the bulk-hiring track. SP doubles the package and demands a stronger coding performance in the online test; InfyTQ certification holders are preferred for SP consideration. PP is offered to top HackWithInfy scorers and InfyTQ performers (typically 7.5+ CGPA).

The technical interview follows the online test. If you need the written-test section pattern before you reach the interview stage, the Infosys placement papers with solutions cover the format question-by-question.

OOP and Language Fundamentals

Every Infosys technical interview opens with: “Which programming language are you most comfortable with?” Your answer sets the direction for the next 20 minutes. C, C++ and Java are the common choices.

C vs Java

• Q: What are the key differences between C and Java?

  • Answer: C is procedural; Java is object-oriented. Java includes exception handling; C has no built-in mechanism for it. Java manages memory through garbage collection; in C, allocated memory must be freed explicitly using free(). Java does not support preprocessors; C and C++ use them via the # symbol. Java is platform-independent through the JVM; C-compiled binaries are platform-specific.

• Q: What does platform independence mean in Java?

  • Answer: Java source code compiles to bytecode, not machine code. The JVM on each target platform interprets that bytecode at runtime. One codebase runs on Windows, Linux or macOS without recompilation.

The four OOP pillars

Interviewers expect real-world examples, not textbook definitions. Prepare a short concrete illustration for each.

• Q: Explain inheritance with an example.

  • Answer: A Dog class extends an Animal class, inheriting breathe() and eat() without rewriting them. Java supports single and multilevel class inheritance; multiple inheritance is achieved through interfaces rather than classes.

• Q: What is polymorphism?

  • Answer: One interface, multiple forms. Compile-time polymorphism (method overloading): same method name, different parameter signatures. Runtime polymorphism (method overriding): a subclass supplies its own implementation of a parent-class method, resolved at runtime.

• Q: What is the difference between encapsulation and abstraction?

  • Answer: Encapsulation bundles data and methods in one unit and restricts direct access using private fields with public getters and setters. Abstraction hides implementation details and exposes only the necessary behaviour through abstract classes or interfaces. An ATM is a clean abstraction example: you call withdraw() without knowing the internal cash-dispensing logic.

• Q: What is an abstract class?

  • Answer: A class that cannot be instantiated directly. It may contain abstract (unimplemented) methods that subclasses must implement, plus concrete methods with shared logic. Useful when you want to enforce a contract while providing common behaviour.

The logical and aptitude sections in the online test precede the interview. Infosys logical reasoning questions covers the reasoning section pattern in detail.

DBMS: Normalisation, Keys and Triggers

DBMS questions appear in every SE-track technical interview and in most SP interviews.

Normalisation walkthrough

• Q: Walk me through normalisation up to BCNF.
  • 1NF: Eliminate repeating groups; each column holds atomic values; every row is unique.
  • 2NF: Satisfies 1NF; every non-key attribute is fully dependent on the entire primary key, removing partial dependencies.
  • 3NF: Satisfies 2NF; no transitive dependencies — non-key attributes depend only on the primary key, not on other non-key attributes.
  • BCNF (3.5NF): Satisfies 3NF; every determinant is a candidate key. Resolves anomalies that 3NF misses when there are multiple overlapping candidate keys.

Keys and constraints

• Q: Difference between primary key and unique key?

  • Answer: Both enforce uniqueness within a column. A primary key cannot hold NULL and a table may have only one. A unique key allows one NULL value and a table may have multiple unique keys.

• Q: What is a foreign key?

  • Answer: A column in one table that references the primary key of another table, enforcing referential integrity. You cannot insert a foreign key value that does not exist in the referenced table.

• Q: What is a SQL trigger?

  • Answer: A stored procedure that fires automatically when an INSERT, UPDATE or DELETE event occurs on a specified table. The DBMS executes it without an explicit call; triggers are typically used to enforce business rules or log data changes.

OS and Data Structures

OS conceptual questions surface in SE and SP interviews; DSA often includes a live coding problem at the SP and PP levels.

Operating systems

• Q: What is a deadlock? What are the four necessary conditions?

  • Answer: A deadlock is a state in which two or more processes wait indefinitely for resources held by each other. The four Coffman conditions (all four must hold simultaneously): mutual exclusion, hold and wait, no preemption, and circular wait. Removing any one condition breaks the deadlock.

• Q: What is the difference between a process and a thread?

  • Answer: A process is an independent program in execution with its own memory space. A thread is a lighter unit of execution within a process and shares the process’s memory. Context-switching between threads is cheaper than between processes.

• Q: What is virtual memory?

  • Answer: A technique that maps virtual addresses to physical addresses, allowing a process to use more memory than is physically available. Pages of data are moved to disk when RAM is full and loaded back on demand.

Data structures

• Q: What is a linked list?

  • Answer: A linear data structure in which each node stores a value and a pointer to the next node. The last node points to NULL. Unlike arrays, linked lists do not require contiguous memory; the trade-off is O(n) access time versus O(1) for arrays.

• Q: When would you use a stack instead of a queue?

  • Answer: Stack (LIFO) suits function-call management, undo operations and expression evaluation. Queue (FIFO) suits task scheduling, breadth-first search traversal and print spoolers. The choice follows the access pattern the problem demands.

• Q: What is the time complexity of binary search?

  • Answer: O(log n). The sorted array is halved at each step. Binary search requires sorted input; if the input is unsorted, sorting first costs O(n log n).

Number series and aptitude pattern questions appear in the online test before the interview; clear that hurdle first.

The 2026 Hiring Shift: AI-Attuned Skills

Infosys onboarded 20,000 freshers in FY26 and has the same target for FY27, per CEO Salil Parekh’s Q4 FY26 earnings commentary. Two details from that commentary matter if you are targeting SP or PP: Infosys is setting differentiated starting compensation for candidates with skills more attuned to AI, and is building a pool of forward-deployed engineers to do AI solution work directly with clients.

The practical read: OOP, DBMS and OS fundamentals still drive SE selection. For PP, the interview tests whether you can build something and reason about it, not just recall definitions.

For the full campus drive timeline and eligibility criteria, the Infosys off-campus and referral drive guide covers the application process.

The PP track’s emphasis on building over reciting definitions fits a broader pattern across Indian IT hiring in 2026. If you want to test whether you can ship an AI feature before your placement window, TinkerLLM is a hands-on platform at ₹299; the output is closer to what forward-deployed AI roles actually require than any definition-and-answer drill session. For the structured path from CS fundamentals to deployed AI work, the 2026 AI roadmap for Indian engineering students lays out the sequence.