High Concurrency & Transactional Resilience in Fintech Platforms

1. Problem & Context In financial systems, absolute data integrity and deterministic transaction completion are non-negotiable. Balance deductions, audit logging, and receipt dispatch must occur inside atomic ACID transaction boundaries.

2. Optimistic vs Pessimistic Locking Under peak concurrency, traditional database locks cause deadlocks. We apply version-checked optimistic concurrency control paired with Redis-backed distributed locks.

3. Conclusion With strict isolation levels and idempotency keys, duplicate charges and inconsistent states are eliminated across network partitions.