Payment authorization infrastructure -- routing, validation, message formats, and operational patterns at card-network scale.
2026
Apr
Designing Rate Limiters for Payment Systems
distributed-systems
838 words
How to build rate limiters that protect authorization infrastructure without rejecting legitimate traffic. Token bucket math, sliding window trade-offs, and the distributed coordination problem.
Understanding ISO 8583 Bitmap Parsing
payments
281 words
How payment networks encode field presence using primary and secondary bitmaps in binary messages.
Feb
Why UUIDs Matter for Idempotency
payments
188 words
Using UUID v7 as idempotency keys in payment authorization to prevent duplicate processing.