Chargebee

Role: Software Engineer

College: Not Specified

Interview Date: November - December 2025 (Rounds occurred)

Interview Type: Full-Time

Result: Declined Offer

Difficulty: Medium-Hard

Rounds: 5 rounds

Topics Asked: Core Java/OOPs, Multithreading, Collections, System Design, SOLID principles, DSA, API Designing, Scenario-based questions, Output-based questions, Project discussion, Managerial questions, Puzzles.

Experience:

This candidate interviewed with Chargebee in late 2025 and shared a detailed breakdown of their experience.

Round 1: Online Test (Not explicitly detailed in search results, but implied as a screening step before virtual technical interview)

Round 2: Virtual Technical Interview 1 (Nov 19, 1 hour)

Questions covered Core Java/OOPs (Multithreading, Collections, all OOPs concepts with real-life examples). Scenario-based questions included choosing between NoSQL and MySQL for specific software features and explaining the choice (e.g., why MongoDB over MySQL). A simple DSA problem was given, with the interviewer focusing more on the test cases written. Output-based questions involved code snippets where the candidate had to identify the output or error. Project discussion and API Designing were also part of this round.

Round 3: On-site Technical Interview 2 (Dec 5, 1 hour)

This round focused on System Design, specifically designing a subscription management system (handling adding/canceling subscriptions, amount calculation). The interviewer emphasized logic, clean code, OOPs, and SOLID implementation. Many questions were asked about SOLID principles. DSA questions revolved around real-life use cases of Tree and Graph data structures.

Round 4: On-site Technical Interview 3 (Not dated, but likely around Dec 5)

System design included designing a Parking Lot system that initially handles Cars and Bikes, and later Trucks. A specific scenario was presented: if all bike spaces are occupied, one car space can be used for two bikes. The interviewer was keen on how to handle concurrent slot allotment requests. The main focus was on database design and concurrency handling. Other topics included Map Matching (Viterbi algorithm, scaling), JWT, and Shared Secret Key discussions.

Round 5: Managerial Interview (Dec 5, 45 min)

This round was conducted by a Senior VP of Engineering. It began with a resume walkthrough and detailed discussions on various projects. Managerial questions included "Why join Chargebee when you have an offer from Informatica?", "How to manage conflict?", and "What would your manager say about you?". A puzzle was also given: identifying a lighter ball out of 9 using a scale in minimum weighings, with a modification where the odd ball could be heavier or lighter. The candidate received an offer letter two days later but decided to respectfully decline it.