Building PCI-DSS Level 1 Compliant Fintech Backends
Handling cardholder data (CHD) requires strict adherence to PCI-DSS v4.0 standards. Failing an audit leads to astronomical fines and revoked merchant capabilities. Here is how we engineer compliant payment vaults.
1. Tokenization & Cardholder Data Isolation
Never store primary account numbers (PAN) or CVV strings in your primary database tables. Instead, route payment payloads through isolated, single-purpose AWS KMS or HashiCorp Vault tokenization services that return non-sensitive token hashes.
2. Network Segmentation & VPC Peering
Isolate the Cardholder Data Environment (CDE) inside a dedicated AWS VPC with restricted Security Groups and VPC peering rules. Only specific microservices with mutual TLS (mTLS) authentication can communicate with the CDE vault.
Security Architecture Checklist
Enforce TLS 1.3 in transit, AES-256 at rest with automated key rotation every 90 days, immutable CloudTrail audit logs, and zero plain-text logging.