Creatio India Software Engineer Interview: Rounds, Questions and Preparation

What the job involves

As a Software Engineer at an Indian SaaS or B2B product company, you will build and maintain features for multi-tenant web applications used by business customers. Day to day you will write code, fix bugs, review pull requests, and work with product and QA teams to ship reliable releases. You will also learn to handle scalability, data security, and integrations that are common in B2B products.

Role and technical knowledge

1. 1

   What is multi-tenancy in a SaaS product, and how would you ensure one customer's data is not visible to another?

   Explain that multi-tenancy means one application instance serves many customers. Mention tenant IDs, row-level security, and separate database schemas or databases as common isolation strategies.

2. 2

   Explain the difference between REST and SOAP APIs, and which one you would choose for a B2B integration.

   Cover that REST is lightweight, uses JSON, and is easier for web and mobile clients. SOAP is heavier, uses XML, and has built-in standards for security and transactions. For most modern B2B products, REST is preferred unless strict WS-Security is required.

3. 3

   How would you design a database schema for a simple CRM module that stores leads, contacts, and accounts?

   Describe tables for leads, contacts, and accounts with primary keys and foreign key relationships. Mention indexing on frequently queried columns and handling one-to-many relationships.

4. 4

   What is the difference between authentication and authorization, and how do they apply in a B2B product?

   Authentication verifies who the user is, authorization decides what they can access. In B2B, roles like admin, manager, and user often control access to features and data.

Practical scenarios

1. 5

   A customer reports that their dashboard is slow only when they have more than 10,000 records. How would you debug and fix this?

   Start by checking database queries for missing indexes or N+1 problems. Then look at pagination, caching, and whether the API returns unnecessary data. Suggest profiling tools and load testing.

2. 6

   You need to add a new field to an existing API response without breaking current mobile app clients. How do you approach this?

   Explain backward compatibility: add the new field as optional, keep old fields, and version the API if needed. Mention communication with client teams and testing with old app versions.

3. 7

   Your team wants to add a third-party payment gateway to the product. What steps would you take from a software engineering perspective?

   Cover reading the gateway's API docs, handling authentication keys securely, writing integration code with retries and idempotency, and testing sandbox and error scenarios.

4. 8

   How would you write a unit test for a function that calculates the total invoice amount including tax and discounts?

   Describe test cases for normal values, zero values, negative discounts, and rounding. Mention using a testing framework like JUnit or pytest and mocking external dependencies.

Behavioural and HR

1. 9

   Why do you want to work in a SaaS or B2B product company instead of a services company?

   Show interest in building products that scale, working with continuous releases, and learning about business workflows. Avoid saying services companies are bad.

2. 10

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

   Use the STAR method: describe the situation, the technology, how you learned it, and the outcome. Highlight self-learning and applying it under a deadline.

3. 11

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

   Focus on respectful discussion, using data or prototypes to compare options, and being willing to accept the better idea. Show teamwork over ego.

4. 12

   Where do you see yourself in three years as a software engineer in a product company?

   Mention growing into a stronger developer, owning modules, mentoring juniors, and understanding the business domain. Align your goals with the company's product growth.

Coding and problem solving

1. 13

   Given a list of customer records, write a function to find all customers whose email domain is 'example.com'.

   Use a simple loop or filter, handle case insensitivity, and consider edge cases like missing emails. Explain time complexity.

2. 14

   How would you reverse a linked list, and why is this relevant in real software?

   Describe iterative and recursive approaches. Mention that linked lists appear in memory management and that the problem tests pointer manipulation and edge cases.

3. 15

   Write a SQL query to find the top 5 customers by total order value in the last month.

   Use JOIN between customers and orders, filter by date, GROUP BY customer, SUM order value, ORDER BY descending, and LIMIT 5. Mention handling NULLs and indexes.

4. 16

   Explain how you would detect if a string has balanced parentheses, and give an example of where this is used in a product.

   Use a stack: push opening brackets, pop on closing, and check empty at the end. Mention use in expression parsers, formula builders, or configuration validators.