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 • 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

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

#Database Theory #Transactions
Practice
Data Engineer • Coding • medium

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

#Window Functions #Subqueries #SQL Server
Practice
Data Engineer • Coding • easy

Given an Employee table with columns Id, Name, Salary, and ManagerId, write a query to find all employees who earn more than their direct managers.

#Self Joins #Filtering
Practice
Data Engineer • Coding • medium

Write a query to find the 7-day moving average of sales for a retail client.

#Window Functions #Moving Averages #Data Analysis
Practice
Data Engineer • Coding • medium

Write a SQL query to calculate the cumulative sum of sales per region over time.

#Window Functions #Aggregation #Time Series
Practice
Data Engineer • Technical • easy

Explain the exact differences between RANK(), DENSE_RANK(), and ROW_NUMBER() in SQL. Provide a scenario where you would choose DENSE_RANK() over RANK().

#Window Functions #Ranking
Practice
Data Engineer • Technical • hard

You have a slow-running query in Snowflake with multiple joins and a subquery that processes millions of rows. How do you approach optimizing it?

#Query Optimization #Execution Plan #Snowflake
Practice
Data Scientist • Coding • medium

Write a SQL query to calculate the 7-day rolling average of daily sales for an e-commerce platform.

#SQL #Window Functions #Time Series
Practice
Data Scientist • Coding • medium

Write a SQL query using window functions to find the second highest salary in each department.

#SQL #Window Functions #Data Aggregation
Practice
Data Scientist • Coding • medium

Write a SQL query to find the top 3 employees with the highest sales in each department.

#SQL #Window Functions #Ranking
Practice
Data Scientist • Coding • easy

Write a SQL query to find all duplicate records in a table based on an 'email' column, and return the email along with the count of duplicates.

#SQL #GROUP BY #HAVING
Practice
Full Stack Engineer • Coding • easy

Write a SQL query to find the second highest salary of an employee from an Employee table.

#Database #Queries #Aggregations
Practice
Machine Learning Engineer • Coding • medium

Write a SQL query to find the top 3 most frequent product categories in a transaction table, partitioned by month.

#SQL #Window Functions #Data Aggregation
Practice
Product Manager • Coding • medium

Given a 'users' table and a 'logins' table, write a query to find the percentage of active users who logged in more than 5 times this week.

#Joins #Subqueries #Ratios
Practice
Product Manager • Coding • easy

Write a SQL query to find the top 5 clients by revenue generated in the last quarter from a 'transactions' table.

#Data Extraction #Aggregations #Filtering
Practice

Difficulty Radar

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Meet Your Interviewers

The "Standard" Interviewer

Senior Engineer

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

Simulate

Unwritten Rules

Think Out Loud

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

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