The original title is "Building a Conflict-Safe Notes App with Supabase and Vanilla JavaScript"

Short summary

Tutorial showing how to build conflict-safe multi-user editing using Supabase, PostgreSQL triggers, and atomic compare-and-swap logic. A single extra WHERE clause in the UPDATE statement detects simultaneous edits: if two clients modify the same row, the second write returns an empty result (not an error), signaling a conflict. The key insight: SQL triggers handle atomicity server-side, JavaScript handles client-side interpretation—no locking needed.

• •SQL triggers stamp updates with server timestamps, enabling atomic conflict detection at the database layer
• •Conflict detection via compare-and-swap: UPDATE WHERE id = X AND updated_at = Y returns empty array on mismatch
• •Supabase realtime syncs multiple clients without custom server infrastructure or application-level locking

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