CashFree SDET Role
Summary
I recently interviewed for an SDET position at CashFree. The process included four rounds, covering coding challenges, in-depth technical discussions on various CS fundamentals, and a final HR interaction. I successfully cleared all rounds and received an offer.
Full Experience
My interview journey at CashFree began with Round 1, which featured two coding questions. I managed to solve one: finding all palindromic substrings in a given string, which was a LeetCode Medium problem. The second was a hard DP problem where I explained two approaches but couldn't fully solve it even with a hint.
Round 2 also consisted of three coding challenges. I successfully solved 'Search in Rotated Sorted Array' (LeetCode Medium) and 'Find the Cheapest Flights With K Stops' (LeetCode Medium). The third question was 'Edit Distance', a LeetCode Hard DP problem, which I also managed to solve.
In Round 3, the discussion moved beyond coding. We delved into my internship experiences and projects. The interviewer also tested my fundamental knowledge across various computer science domains, including RDBMS, OOPS, Computer Networks, and Operating Systems. Specific questions included: 'Why do we use HTTP?', 'What's the difference between WebSocket and HTTP?', 'Why do we create different schemas?', 'What's the difference between SQL and NoSQL?', and a discussion on different paging algorithms. I was also asked to write a few SQL queries.
The final Round 4 was with HR. We discussed my future career goals, my interest in the Fintech industry, and specifically why CashFree. We also touched upon my hobbies and other general topics.
Following these rounds, I awaited the results and was pleased to receive an offer with a CTC of 22 lacs, including a 10 lac base and 1 lac variable.
Interview Questions (9)
Given a string, find all possible palindromic substrings within it.
Given a sorted array that has been rotated at some unknown pivot, search for a target element's index.
Given a list of flights and their costs, find the cheapest price to travel from a source city to a destination city with at most K stops.
Given two strings word1 and word2, return the minimum number of operations required to convert word1 to word2. The allowed operations are insert a character, delete a character, or replace a character.
Explain the fundamental reasons and role of HTTP in web communication.
Describe the key differences between HTTP and WebSocket protocols, including their connection models, use cases, and advantages/disadvantages.
Explain the reasons and benefits behind creating and using different schemas in a database system (e.g., for organization, security, access control).
Discuss the fundamental differences between SQL (relational) and NoSQL (non-relational) databases, covering aspects like data models, scalability, flexibility, and typical use cases.
Discuss various paging algorithms used in operating systems for memory management, explaining their principles and common examples (e.g., FIFO, LRU, Optimal).