Scrut Automation Software Engineer Interview: Rounds, Questions and Preparation

What the job involves

Software Engineers at Indian SaaS and B2B product companies build and maintain web applications, APIs, and integrations that power business workflows. Day to day, they write clean code, debug issues, collaborate with product and QA teams, and deploy features that help customers automate manual processes. Freshers typically start with well-defined tasks and grow into owning modules.

Role and Technical Knowledge

1. 1

   What is the difference between a monolithic and a microservices architecture? Which one would you prefer for a fast-growing SaaS product and why?

   Explain that monoliths are simpler to start but harder to scale, while microservices offer independent scaling and deployment. Mention that early-stage SaaS often starts with a monolith and moves to microservices as teams grow.

2. 2

   How would you design a simple REST API for a customer onboarding feature in a B2B SaaS tool?

   Cover endpoints like POST /customers, GET /customers/{id}, proper HTTP methods, status codes, authentication, and input validation. Show awareness of multi-tenancy and data isolation.

3. 3

   Explain the concept of database indexing. How would you use it to speed up a query that fetches all open tickets for a specific customer?

   Describe indexes as data structures that speed up reads. Suggest a composite index on customer_id and status, and note the trade-off of slower writes.

4. 4

   What are webhooks and how are they useful in a SaaS integration platform?

   Define webhooks as user-defined HTTP callbacks triggered by events. Explain how they enable real-time data sync between a SaaS product and third-party tools like Slack or Jira.

Practical Scenarios

1. 5

   A customer reports that their automated compliance report is missing some data. How would you debug this issue?

   Outline a systematic approach: reproduce the issue, check logs, verify data inputs, inspect the query or API call, and test edge cases. Mention communicating progress to the customer.

2. 6

   You need to add a feature that lets users export data to CSV. Walk me through your implementation steps.

   Cover requirements gathering, choosing a library, handling large datasets with streaming, setting proper headers, and testing with different data sizes. Mention security around data access.

3. 7

   How would you handle a situation where your code works locally but fails in production?

   Talk about environment differences, configuration management, logging, and using staging environments. Emphasize checking environment variables, dependencies, and permissions.

4. 8

   You are asked to improve the performance of a slow page that loads a list of audit logs. What steps would you take?

   Suggest pagination, lazy loading, database query optimization, caching, and frontend rendering improvements. Mention measuring before and after with tools like Chrome DevTools.

Behavioural and HR

1. 9

   Why do you want to work in a fast-growing SaaS company like Scrut Automation rather than a large service-based IT firm?

   Show enthusiasm for product ownership, rapid learning, and direct impact. Mention interest in solving real business problems and working in a dynamic environment.

2. 10

   Tell me about a time you had to learn a new technology quickly for a project. How did you approach it?

   Use the STAR method. Highlight self-learning through documentation, tutorials, and small prototypes. Emphasize persistence and applying the learning to deliver results.

3. 11

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

   Focus on respectful communication, data-driven discussion, and willingness to compromise. Show that you prioritize the team's goal over being right.

4. 12

   Where do you see yourself in three years in a product-based company?

   Express a desire to grow into a strong individual contributor or tech lead, deepen domain knowledge, and contribute to architecture decisions. Align your goals with the company's growth.

Coding and Problem Solving

1. 13

   Given a list of customer IDs and their purchase amounts, write a function to find the top K customers by total purchase amount.

   Discuss using a hash map to aggregate totals, then a heap or sorting to find top K. Mention time and space complexity.

2. 14

   How would you reverse a linked list? Explain your approach and write pseudocode.

   Cover iterative and recursive methods. Explain pointer manipulation and edge cases like empty list or single node.

3. 15

   Write a SQL query to find all users who have not logged in for the past 30 days from a users table with a last_login timestamp.

   Use a WHERE clause with DATE_SUB or equivalent. Mention handling NULLs and indexing the last_login column for performance.

4. 16

   Given a string, find the first non-repeating character. What is the time complexity of your solution?

   Use a hash map to count frequencies, then iterate to find the first with count 1. Explain O(n) time and O(1) space for fixed character set.