Offline Concurrency Strategy Selector

When to Use

This skill applies whenever a business transaction spans multiple system transactions — the user loads a record in one HTTP request, works with it (seconds to hours), and saves in a later request. During that gap, the database cannot protect against another user modifying the same data. You need application-level concurrency control.

Use this skill when designing new editing workflows, diagnosing "lost update" bugs, or auditing existing lock strategies. It selects among four patterns from Fowler's Patterns of Enterprise Application Architecture Ch 16 and routes to child implementation skills when needed.

Do not use if the entire user workflow fits in a single request/transaction — standard database isolation levels are sufficient and far simpler.

Context & Input Gathering

Gather the following before proceeding. If working from a codebase, grep for session state, version columns, and lock tables. Otherwise, ask the user directly.