Tech Mahindra
Multinational IT services and consulting company.
4 Rounds
~21 Days
Medium
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
Data Engineer
•
Coding
•
hard
Write a PySpark snippet to merge new incoming data into an existing Delta Lake table, updating existing records and inserting new ones (Upsert).
#Delta Lake
#PySpark
#Upserts
Data Engineer
•
Technical
•
hard
During a data migration project, your PySpark job is running extremely slow and some tasks are taking much longer than others. How do you identify and resolve data skewness?
#Performance Tuning
#Data Skew
#Salting
Data Engineer
•
Technical
•
medium
What is the difference between a Broadcast Hash Join and a Sort Merge Join in Spark? When would you force a Broadcast join?
#Spark Joins
#Optimization
Data Engineer
•
Technical
•
medium
Explain the internal architecture of Apache Spark. What happens under the hood when you submit a Spark job?
#Spark Architecture
#Driver
#Executors
#Cluster Manager
Data Engineer
•
Technical
•
easy
Explain the concept of Lazy Evaluation in Spark. Why is it beneficial for performance?
#Spark Core
#Transformations vs Actions
Data Engineer
•
Technical
•
hard
Your Spark job fails with an OutOfMemory (OOM) error on the executor side. What parameters would you tweak or what code changes would you make?
#Troubleshooting
#Memory Management
#Spark Configuration
Data Engineer
•
Technical
•
easy
In PySpark, what is the difference between repartition() and coalesce()? When should you use which?
#PySpark
#Partitioning
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.