Design a Scalable Idempotent Ledger Service
Company: Stripe
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Overview: Design a scalable internal double-entry ledger with immutable debit and credit postings, idempotent retried writes, and balances labeled by freshness. Address transaction atomicity, hot accounts, shard boundaries, compensating entries, reconciliation, and recovery without relying on an external payment processor.