2024-11-03 · Haruka Watanabe
Blue-green migrations without losing the plot
Keeping shadow schemas honest when ORMs generate silent alterations.
Blue-green database cuts fail more often on communication than on technology. The shadow stack needs the same constraints as production, not a relaxed cousin that passes CI by accident.
We teach a three-column diff habit: ORM migration file, generated SQL, and catalog reality from pg_dump --schema-only. If any column disagrees, promotion pauses. Sounds heavy until you compare it to a weekend rollback.
For teams in Japan balancing JST business windows with global vendors, we also recommend explicit handoff timestamps in UTC and JST. Small detail, fewer mistaken promotions.
Tags: Migrations, Process