Teradata India Software Engineer Interview: Rounds, Questions and Preparation

What the job involves

Software Engineers in global tech companies build, test, and maintain scalable software systems that power products and internal platforms. Day to day, they write code, review peers' work, debug production issues, and collaborate with product and QA teams to ship reliable features. Freshers typically start on well-defined components, learning the codebase, tools, and engineering practices while contributing to real deliverables.

Role and Technical Knowledge

1. 1

   Explain the difference between a primary key, a unique key, and a foreign key in a relational database.

   Define each constraint, mention nullability and indexing differences, and give a small example table where each is used.

2. 2

   What happens when you run a SQL query with a JOIN on two large tables? How would you optimise it?

   Describe join algorithms like hash join and nested loop, then suggest indexing join columns, filtering early, and avoiding SELECT *.

3. 3

   Compare process and thread. Why would a software engineer care about this distinction?

   Cover memory isolation, context-switch cost, and how it affects concurrency, performance, and bug patterns in server code.

4. 4

   What is the time complexity of common operations on arrays, linked lists, hash maps, and balanced trees?

   Give average and worst-case Big-O for insert, delete, and search, and mention when you would choose each structure.

Practical Scenarios

1. 5

   You are asked to fix a bug that only appears in production but not in your local environment. How do you approach it?

   Show a structured method: reproduce with logs or metrics, compare environments and configs, form a hypothesis, and test safely in staging.

2. 6

   A feature you wrote passes all tests but slows down a critical API by 40 percent. What do you do?

   Mention profiling to find the bottleneck, checking database queries and N+1 patterns, adding caching or batching, and validating with load tests.

3. 7

   You need to add a new column to a large table that is live in production. How do you roll it out safely?

   Discuss backward-compatible schema changes, default values, phased deployment, backfilling in batches, and rollback planning.

4. 8

   How would you design a simple URL shortener that handles millions of redirects per day?

   Cover unique key generation, a key-value or relational store, caching hot URLs, and basic load balancing and read replicas.

Behavioural and HR

1. 9

   Tell me about a time you had to learn a new technology quickly for a project or internship.

   Use STAR format, name the technology, explain your learning method, and quantify the outcome such as meeting a deadline or improving a metric.

2. 10

   Describe a situation where you disagreed with a teammate on a technical approach. How did you handle it?

   Focus on listening, presenting data or trade-offs, and committing to the team decision even if it was not your first choice.

3. 11

   Why do you want to work as a software engineer in a global product company rather than a services firm?

   Connect your interest in building long-term products, working with large-scale systems, and learning from strong engineering practices.

4. 12

   Where do you see yourself in three years, and how does this role fit your plan?

   Show realistic growth such as deepening technical expertise, owning modules, and mentoring juniors, while tying it to the company's engineering culture.

Coding and Problem Solving

1. 13

   Given an array of integers, find two numbers that add up to a target sum. Explain your approach and complexity.

   Start with brute force, then optimise using a hash map for O(n) time, and discuss edge cases like duplicates and no solution.

2. 14

   Write a function to detect if a linked list has a cycle. What is the time and space complexity?

   Explain Floyd's cycle detection with slow and fast pointers, O(n) time and O(1) space, and mention how to find the cycle start.

3. 15

   How would you find the second highest salary from an employee table using SQL?

   Show a subquery or window function approach, handle ties and nulls, and explain why LIMIT or TOP alone can be incorrect.

4. 16

   Explain how you would reverse a string in place and then check if it is a palindrome.

   Cover two-pointer swapping, Unicode and case handling, and the difference between in-place and extra-space solutions.