> ## Documentation Index
> Fetch the complete documentation index at: https://knowledge-base-starter-mintlify-85d166f9.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Deployment

> How code goes from a merged PR to production, and how to roll back when something goes wrong.

We use a trunk-based deployment model. Merging to `main` triggers a staging deploy automatically; production deploys are triggered manually after verification.

## Flow overview

```
feature branch → PR review → merge to main → auto-deploy to staging → manual promote to production
```

## Deploying to staging

Every merge to `main` triggers a staging deployment automatically via CI. You don't need to do anything. Check the `#deploys` Slack channel for status notifications.

Staging deployments take approximately 5–10 minutes. If a deploy fails, CI will post the error in `#deploys` with a link to the failed run.

## Promoting to production

Once a change is verified in staging:

1. Go to the deploy tool (link in `#deploys` channel description).
2. Select the staging build you want to promote.
3. Click **Promote to production**.
4. Monitor the `#deploys` channel for confirmation or errors.

Production deploys require at least one engineer who didn't author the change to click promote. This is a soft guard — use judgment in an emergency.

## Feature flags

Most new features are deployed behind a feature flag to decouple deploy from release. Flags are managed in \[Flag Tool Name]. Ask your tech lead about the flag naming convention and cleanup process.

## Rollbacks

If a production deploy causes an incident:

1. Use the deploy tool to roll back to the previous production build immediately.
2. Don't wait to diagnose — roll back first, investigate after.
3. File an [incident](/engineering/incident-response) and start a postmortem if users were affected.

Rolling back takes about 2 minutes. It's safe and reversible — do it early.

## Database migrations

Migrations run automatically as part of the deploy pipeline. Backward-incompatible migrations require a multi-phase deploy — ask in `#eng` before merging if your migration drops a column or changes a type.

## Deploy freeze windows

We freeze production deploys during major events or the last business day before a holiday. The `#deploys` channel will pin a message when a freeze is active.