Dual-Layer Locking: Redis for Speed, PostgreSQL for Reliability

Two users withdraw money from the same account at exactly the same moment. Your system processes both requests, your database balance goes negative, and you wake up to an incident report. Sound familiar?

What if you could combine Redis's millisecond response times with PostgreSQL's bulletproof consistency? This dual-layer locking pattern does exactly that, giving you both speed and safety.

In this post, we'll explore a pattern that combines Redis's speed with PostgreSQL's reliability to prevent race conditions at scale.