SKILL-100 Data modeling and migrations Locked skill

Zero-downtime migrations

Never make old and new code disagree about the schema at the same instant — expand first, switch, then contract across separate deploys.

01

What this skill helps you build

Change your production schema without taking the app down — using the expand/contract pattern to avoid blocking locks while traffic is live.

The production takeaway

Never make old and new code disagree about the schema at the same instant — expand first, switch, then contract across separate deploys.

02

Inside this skill

The full skill expands these implementation areas with decisions, edge cases, prompts, tests, and framework-specific code.

Data modeling and migrations
What this helps you build

A safe schema change workflow for a database that is serving live traffic. Instead of one big migration that locks a table and risks downtime or a failed deploy , you split every b

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Data modeling and migrations
When to use this

Use this any time a migration would otherwise a hold a lock that blocks reads or writes, or b make the running application code disagree with the schema for even a moment. In pract

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Data modeling and migrations
The core idea

A rolling deploy means old code and new code run simultaneously for a few seconds to a few minutes. The schema must be compatible with both the entire time. A single migration that

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03

Unlock the full implementation

Paid access includes the complete skill body, implementation prompt, common mistakes, production checklist, and code examples where this skill includes them.