Axiom Database Migration

This handles the scary part of database migrations: changing schemas when you already have real user data in production. The core philosophy is solid: migrations are immutable once shipped, so you make them additive and idempotent instead of destructive. It walks you through the common gotchas like why you can't just add a NOT NULL column to a table with existing rows, and shows you the safe pattern of adding nullable columns first, backfilling data, then tightening constraints later. If you've ever stared at a migration error at 2am wondering if you're about to lose customer data, this is the guardrails you wish you had earlier.