Payment and Transaction Security Questions

Design and evaluate secure payment and transaction systems including architecture, controls, and detection. Key topics include end to end payment flow design, trustworthy boundaries for cardholder data, tokenization and cryptographic protections, secure key management and secrets handling, safe integrations with third party payment processors and gateways, reconciliation and dispute handling patterns, chargeback and fraud workflows, real time fraud detection and scoring models, velocity and rule based controls, monitoring and alerting for anomalous transactions, testing and auditability, and compliance considerations such as the Payment Card Industry Data Security Standard. Candidates should be able to specify technical controls, observability strategies, and trade offs between friction and fraud risk.