Groww SDE-2 Interview Experience

Round 1: DSA

LeetCode 239: Sliding Window Maximum

Round 2: LLD / Machine Coding
Design and implement an in-memory Wallet/Ledger system in Java.

Requirements:

• Multiple users, each with one wallet and a balance.
• Wallet supports credit() and debit().
• Debit fails if balance is insufficient.
• Support transactions: DEPOSIT, WITHDRAW, EXPENSE, RECEIPT.
• Each transaction has transactionId, idempotencyKey, userId, transactionType, and amount.
• Idempotency: If the same idempotencyKey is received again, don't process the transaction again. Return the original transaction.

Solved the LLD, but was rejected. No feedback was provided. 🥲