deployment-engineer

---
name: deployment-engineer
description: Deployment automation specialist for CI/CD pipelines and infrastructure. Use when setting up deployment, configuring CI/CD, or managing releases.
license: MIT
---

# Deployment Engineer

Specialist in deployment automation, CI/CD pipelines, and infrastructure management.

## Permission Boundary

Planning, generating configuration, and running read-only validation do not authorize
deployment. Never push, deploy, roll back, change production infrastructure, or alter
remote release state without explicit user approval for that exact action and target.
Before an approved mutation, state the environment, command, expected impact,
verification signal, and rollback path. Stop if the target or authority is ambiguous.

## When This Skill Activates

Activates when you:
- Set up deployment pipeline
- Configure CI/CD
- Manage releases
- Automate infrastructure

## CI/CD Pipeline

### Pipeline Stages

```yaml
stages:
  - lint
  - test
  - build
  - security
  - deploy-dev
  - deploy-staging
  - deploy-production
```

### GitHub Actions Example

```yaml
name: CI/CD

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
      - run: npm ci
      - run: npm run lint

  test:
    runs-on: ubuntu-latest
    needs: lint
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
      - run: npm ci
      - run: npm test

  build:
    runs-on: ubuntu-latest
    needs: test
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
      - run: npm ci
      - run: npm run build
      - uses: actions/upload-artifact@v4
        with:
          name: build
          path: dist/

  deploy-production:
    runs-on: ubuntu-latest
    needs: build
    if: github.ref == 'refs/heads/main'
    environment: production
    steps:
      - uses: actions/checkout@v4
      - uses: actions/download-artifact@v4
        with:
          name: build
          path: dist/
      - run: npm run deploy
```

## Deployment Strategies

### 1. Blue-Green Deployment

```
         ┌─────────┐
         │  Load   │
         │ Balancer│
         └────┬────┘
              │
     ┌────────┴────────┐
     │    Switch       │
     ├────────┬────────┤
     ▼        ▼        ▼
  ┌─────┐ ┌─────┐ ┌─────┐
  │Blue │ │Green│ │     │
  └─────┘ └─────┘ └─────┘
```

### 2. Rolling Deployment

```
┌─────────────────────────────────────┐
│ v1  v1  v1  v1  v1  v1  v1  v1  v1 │ → Old
│ v2  v2  v2  v2  v2  v2  v2  v2  v2 │ → New
└─────────────────────────────────────┘
    ▲                       ▲
    │                       │
  Start                  End
```

### 3. Canary Deployment

```
┌──────────────────────────────────────┐
│ v1  v1  v1  v1  v1  v1  v1  v1  v1  v1 │ → Old
│ v2  v2  v2  v2                        │ → Canary (5%)
└──────────────────────────────────────┘

Monitor metrics, then:
│ v1  v1  v1  v1                        │ → Old (50%)
│ v2  v2  v2  v2  v2  v2  v2  v2  v2  v2 │ → New (50%)
```

## Environment Configuration

### Environment Variables

```bash
# Production
NODE_ENV=production
DATABASE_URL=postgresql://...
API_KEY=${API_KEY}
SENTRY_DSN=https://example.com/123

# Development
NODE_ENV=development
DATABASE_URL=postgresql://localhost:5432/dev
```

### Configuration Management

```typescript
// config/production.ts
export default {
  database: {
    url: process.env.DATABASE_URL,
    poolSize: 20,
  },
  redis: {
    url: process.env.REDIS_URL,
  },
};
```

## Health Checks

```typescript
// GET /health
app.get('/health', (req, res) => {
  const health = {
    status: 'ok',
    timestamp: new Date().toISOString(),
    checks: {
      database: 'ok',
      redis: 'ok',
      external_api: 'ok',
    },
  };

  if (Object.values(health.checks).some(v => v !== 'ok')) {
    health.status = 'degraded';
    return res.status(503).json(health);
  }

  res.json(health);
});
```

## Rollback Strategy

```bash
# Kubernetes
kubectl rollout undo deployment/app

# Docker
docker-compose down
docker-compose up -d --scale app=<previous-version>

# Git
git revert HEAD
git push
```

## Monitoring & Logging

### Metrics to Track

- Deployment frequency
- Lead time for changes
- Mean time to recovery (MTTR)
- Change failure rate

### Logging

```typescript
// Structured logging
logger.info('Deployment started', {
  version: process.env.VERSION,
  environment: process.env.NODE_ENV,
  timestamp: new Date().toISOString(),
});
```

## Scripts

Generate deployment config:
```bash
python3 scripts/generate_deploy.py --env <environment> --name <service-name>
```

Validate deployment:
```bash
python3 scripts/validate_deploy.py --input deploy-plan.md
```

## References

- `references/pipelines.md` - CI/CD pipeline examples
- `references/kubernetes.md` - K8s deployment configs
- `references/monitoring.md` - Monitoring setup