Blue-Green Deployment

A practical example

Example: a team tests a new lead intake service in the green environment using test records.

Before switching live traffic, it checks that both versions understand the same CRM fields and that only the active version sends follow-up messages.

What to evaluate before investing

• Ask which components are duplicated and which state is shared between environments.
• Test traffic switching and rollback while requests and background jobs are in progress.
• Check how schema changes and external writes affect compatibility with the old version.

Limitations and tradeoffs

Parallel environments add capacity and operational work, but costs do not necessarily double. A rollback may require data repair or may be unsuitable after an irreversible change; document those limits before release.