Design a Payment System
Design a Payment System - A Staff playbook focused on idempotent payment flows, double-entry bookkeeping, reconciliation strategies, and regulatory compliance as architectural constraint - not just Stripe integration.
This playbook is part of the full calibration library.
Staff interviews are decided on nuance — tradeoff framing, ownership boundaries, and failure anticipation. This playbook covers the depth that separates Senior from Staff+.
What's inside this playbook
Core sections
- •1. The Staff Lens
- •2. Problem Framing & Intent
- •3. Fault Lines
- •4. Fault Lines (Continued)
- •5. Evaluation Rubric
- •6. Interview Flow & Pivots
- •7. Drills
- •8. Deep Dive Scenarios
- •9. Level Expectations Summary
- •10. Staff Insiders: Controversial Opinions
Appendices
- •Appendix A: Payment State Machine
- •Appendix B: Reconciliation Discrepancy Categories
- •Appendix C: Payment State Machine — Complete Transition Reference
- •Appendix D: Provider Integration Patterns
- •Appendix E: Compliance & Regulatory Considerations
- •Appendix F: Fraud Detection Integration
Practice & Reference
- •How to Use This Playbook
- •Executive Summary
- •System Architecture Overview
- •Interview Walkthrough: How to Present This in 45 Minutes