Chargebee Interview Prep
Curated from real Chargebee interview experiences (Medium, LeetCode Discuss, Glassdoor, AmbitionBox). Covers the DSA problems, system design rounds, and the SQL/OOP/puzzle questions candidates actually got asked — each with a worked-through answer.
1–2 coding (medium/medium-hard), 5 SQL (window functions), aptitude
1 easy–medium DSA problem + discussion on current work & challenges faced
OOP, multithreading, Collections, DB choice (SQL vs NoSQL), 1 DSA/test-case question, API design
System design (subscription mgmt, parking lot, auto-increment IDs), SOLID, real-world DSA (trees/graphs)
Project deep dive, DSA fundamentals, rate limiter / design discussion
Resume walkthrough, conflict handling, culture-fit, brain teasers/puzzles
// Exact rounds vary by level (Intern / SDE1 / SDE2) and location — this is the composite funnel across reported experiences.
DSA Questions
Longest unique substring, circular queue, meeting rooms, prime set-bit counts, knight moves & more — brute force → optimal.
System Design
Subscription management (billing core!), parking lot, auto-increment ID generator, traffic-spike result site, payment retries.
SQL, OOP & Puzzles
Nth highest salary, window functions, OOP/SOLID/multithreading, weighing-balls puzzle, managerial questions.
// Key Takeaways From Real Candidates
Chargebee weighs core CS fundamentals (OOP, multithreading, DB choice, SOLID) as heavily as raw DSA — revise these explicitly, not just patterns.
As a billing company, expect at least one round centered on subscription lifecycle, prorated billing, or payment retry semantics — read the system-design page closely.
Multiple interviewers cared more about the test cases and edge cases you enumerate than the working solution itself.
GitHub repos and old projects get opened live — know why something wasn't deployed or what trade-off you made.