- Ruby on Rails for Web Applications
- Heroku to deploy
- GitHub for source control
- Use Continuous Integration for testing
- Use PostgreSQL database
- Store ISO 8601 compliant time and date
- Monitoring for your server, database
- Self-service for account deletion
- Admin technology to sign in as User
- (Staged) Canary deployment to percentile of your servers (2%, 20%). Canary/Staged Canary to Production could have a 5-minute time window for Engineers to test the change.
- Feature flags to individual user, group of users, percentile of users
- Separate transactional and marketing sender
- Unsubscribe without login
- Confirmed opt-in for marketing mails (GDPR)
- Canary deploy to % of your servers
Finally if your team grows to a point you need to all sorts of data:
- Read replica of your database