Interview Questions › Product Design

Design a digital passport and identity verification system for international travelers

Design an interoperable digital passport and biometric identity ecosystem that allows international air travelers to navigate check-in, border customs control, and boarding gates seamlessly without showing physical paper documents.

Context

International border crossing requires juggling physical passports, visas, vaccination cards, and boarding passes, leading to massive airport bottlenecks and document forgery risks.

Clarifying questions to ask first

• Does the system comply with ICAO Digital Travel Credential (DTC) standards? (Yes).
• What is the fallback for passengers without smartphones? (Physical passport biometric kiosks).

How to approach it

1. Analyze Multi-Stakeholder Ecosystem: International Travelers, Border Control & Immigration Authorities, Airlines, Airport Security (TSA/Interpol)
2. Design Secure Cryptographic & Biometric Architecture: Cryptographically verified digital credential stored in Secure Enclave (ICAO standards), Facial biometric one-to-many boarding verification, Zero-Knowledge Proofs for visa/age validation (proves eligibility without revealing passport number)
3. Design Traveler Mobile Experience: Pre-travel visa & health declaration auto-sync, 1-tap biometric enrollment at home using passport NFC chip scan, Offline encrypted emergency pass backup
4. Address Privacy, Sovereign Government Compliance, and Device Theft Security

Framework: Multi-Stakeholder Requirements -> Cryptographic & Biometric Infrastructure -> Traveler Touchpoints (Check-In, Customs, Boarding) -> Privacy & Sovereign Security -> Metrics

Sample answer

• Biometric facial recognition at departure gates eliminates physical document checks, reducing boarding time from 35 mins to 12 mins per flight
• Zero-knowledge proofs protect citizen privacy while satisfying foreign immigration queries

1. MVP: Passport NFC phone-scan enrollment, encrypted ICAO digital credential, biometric airport seamless lane integration, and automated visa status verification

Executive design: A sovereign-compliant digital travel credential leveraging smartphone NFC passport verification, zero-knowledge proofs, and curb-to-gate biometric facial recognition.

What interviewers look for

• ICAO Cryptographic Security & Zero-Knowledge Architecture
• Facial Biometric Seamless Travel Corridor
• International Interoperability Across Sovereign Border Systems
• Privacy & Data Protection Compliance (GDPR)