HCLTech

Global IT services and consulting company.

4 Rounds ~21 Days Medium
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The Interview Loop

Recruiter Screen (30 min)

Standard fit check, behavioral questions, and resume overview.

Technical Loop (3-4 Rounds)

Deep dive into domain knowledge, coding, and system design.

Interview Question Bank

Backend Engineer • Behavioral • medium

Tell me about a time you had to push back on a client's unrealistic technical requirement or deadline. How did you handle it?

#Communication #Negotiation #Agile
Practice
Backend Engineer • Behavioral • medium

Describe a situation where you had to troubleshoot and resolve a critical production issue under extreme pressure.

#Incident Management #Debugging #Stress Management
Practice
Backend Engineer • Behavioral • easy

How do you approach mentoring junior developers or new joiners in your team?

#Mentorship #Team Building #Code Review
Practice
Backend Engineer • Behavioral • medium

Tell me about a time you had a technical disagreement with a QA engineer or a Product Manager regarding a bug or feature. How was it resolved?

#Conflict Resolution #Collaboration
Practice
Backend Engineer • Behavioral • medium

Explain a recent complex legacy modernization or cloud migration project you worked on. What were the biggest risks and how did you mitigate them?

#Project Management #Risk Mitigation #Architecture
Practice
Backend Engineer • Behavioral • easy

Why do you want to join HCLTech? How do you adapt to working in a global delivery model with different client cultures and time zones?

#Adaptability #Motivation #Global Delivery
Practice
Backend Engineer • Coding • easy

Given an array of integers and an integer target, return indices of the two numbers such that they add up to target. Can you do it in O(n) time complexity?

#Arrays #Hash Table
Practice
Backend Engineer • Coding • medium

Find the length of the longest substring without repeating characters in a given string.

#Strings #Sliding Window
Practice
Backend Engineer • Coding • medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals.

#Arrays #Sorting
Practice
Backend Engineer • Coding • hard

Design and implement a data structure for Least Recently Used (LRU) cache. It should support get and put operations in O(1) time complexity.

#Hash Table #Doubly Linked List #Design
Practice
Backend Engineer • Coding • hard

Given the head of a linked list, reverse the nodes of the list k at a time, and return the modified list.

#Linked List #Recursion
Practice
Backend Engineer • Coding • medium

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

#Heap #Hash Table #Bucket Sort
Practice
Backend Engineer • Coding • medium

Given the root of a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.

#Binary Tree #Breadth-First Search #Depth-First Search
Practice
Backend Engineer • System Design • medium

Design a URL Shortener service like Bitly. Focus on the data model and the algorithm for generating the short URL.

#Scalability #Hashing #Database Design
Practice
Backend Engineer • System Design • hard

Design an API Rate Limiter for a multi-tenant enterprise application to prevent abuse.

#Distributed Systems #Algorithms #Redis
Practice
Backend Engineer • System Design • medium

How would you design a highly available and scalable notification service that sends Emails, SMS, and Push Notifications?

#Asynchronous Processing #Message Queues #Microservices
Practice
Backend Engineer • System Design • medium

Explain the API Gateway pattern. What cross-cutting concerns should be handled at the API Gateway level versus the Microservice level?

#Architecture #Security #Routing
Practice
Backend Engineer • System Design • hard

How do you ensure idempotency in a REST API, specifically for a payment processing endpoint?

#API Design #Idempotency #Payments
Practice
Backend Engineer • System Design • medium

Explain the Circuit Breaker pattern. How does it work, and how would you implement it in a Spring Boot application?

#Fault Tolerance #Resilience4j #Microservices
Practice
Backend Engineer • System Design • medium

Compare Kafka and RabbitMQ. When would you choose Kafka over RabbitMQ for an event-driven architecture?

#Message Brokers #Event Streaming #Kafka
Practice
Backend Engineer • Technical • medium

Explain the internal working of ConcurrentHashMap in Java 8 and how it differs from Java 7.

#Multithreading #Collections #Java 8
Practice
Backend Engineer • Technical • medium

What is the difference between CompletableFuture and ExecutorService in Java? When would you use one over the other?

#Concurrency #Asynchronous Programming
Practice
Backend Engineer • Technical • medium

How does Garbage Collection work in Java? Specifically, explain how the G1 Garbage Collector operates.

#JVM #Memory Management #Garbage Collection
Practice
Backend Engineer • Technical • easy

Explain the complete lifecycle of a Spring Bean from instantiation to destruction.

#Spring Core #IoC #Dependency Injection
Practice
Backend Engineer • Technical • hard

How do you handle distributed transactions across multiple microservices? Explain the Saga design pattern.

#Distributed Systems #Transactions #Saga Pattern
Practice
Backend Engineer • Technical • easy

What is the exact difference between @Controller and @RestController in Spring Boot?

#Spring Web #Annotations
Practice
Backend Engineer • Technical • medium

How does Spring Boot Auto-configuration work under the hood? Which annotations are involved?

#Spring Boot Internals #Auto-configuration
Practice
Backend Engineer • Technical • medium

What is ThreadLocal in Java? Provide a real-world use case for it in a backend web application.

#Concurrency #Web Context
Practice
Backend Engineer • Technical • medium

You encounter a Circular Dependency error in your Spring Boot application. How do you resolve it?

#Dependency Injection #Troubleshooting
Practice
Backend Engineer • Technical • medium

Using Java 8 Streams, given a List of Employee objects (id, name, department, salary), write a snippet to group employees by department and find the highest paid employee in each department.

#Java 8 #Streams API #Lambdas
Practice
Backend Engineer • Technical • medium

Write a SQL query to find the Nth highest salary from an Employee table without using the LIMIT or OFFSET keywords.

#Database #Complex Queries
Practice
Backend Engineer • Technical • medium

Explain the difference between Clustered and Non-Clustered Indexes in a relational database.

#Database Performance #Indexing
Practice
Backend Engineer • Technical • medium

How do you manage and automate database schema migrations in a CI/CD pipeline?

#CI/CD #Database Migrations #Flyway/Liquibase
Practice
Backend Engineer • Technical • medium

What is the N+1 Select problem in Hibernate/JPA, and what are the different ways to fix it?

#Hibernate #JPA #Performance Optimization
Practice
Backend Engineer • Technical • medium

Explain the ACID properties of a database. How do different Isolation levels prevent phenomena like Dirty Reads or Phantom Reads?

#Database Theory #Transactions
Practice

Difficulty Radar

Based on recent AI-sourced data.

Meet Your Interviewers

The "Standard" Interviewer

Senior Engineer

Focuses on core competencies, system constraints, and clear communication.

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Unwritten Rules

Think Out Loud

Always explain your thought process before writing code or drawing architecture.

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