Chargeback Ingestion and a Database Read Bottleneck

Problem: Design a Chargeback Ingestion System Design a system that processes card chargeback/dispute transactions. The system receives chargeback-related transaction events, validates and deduplicates them, tracks their processing state, persists them, and eventually exports eligible transactions into CSV files. These CSV files must be sent to Mastercard via FTP/SFTP. The difficulty felt all righ…

Shared by a candidate · reported Sep 2026. Interview formats change; use it as a guide, not a script.