Why Experienced Engineers Often Avoid Distributed Locks in System Design

A technical analysis argues that the most reliable distributed systems are frequently those that minimize coordination mechanisms rather than rely on complex ones. Engineers are advised to first ask whether a system can be redesigned to eliminate the need for distributed coordination entirely, since every such mechanism adds network overhead, failure scenarios, latency, and operational complexity. For common problems like preventing duplicate database entries, a simple database-level unique constraint can replace a distributed lock by letting the database enforce its own data integrity rules. Similarly, optimistic concurrency control — using version numbers on records — can handle concurrent modifications without requiring exclusive locks. The core principle is that delegating enforcement to the layer that already owns the data is usually simpler, faster, and more dependable than adding external coordination.