Migrations are one of the most overlooked topics in software engineering, especially at high-growth startups and companies. As a company’s operations grow, new systems and approaches are adopted to cope with extra load, more use cases, or more constraints. From time to time, engineers need to migrate over from an old system or approach, to a new one. 

And this is where things can get interesting, unexpected… and even ugly.

This issue is an extensive guide on the process of migration. You can use it as a blueprint when preparing and executing migrations. This guide covers:

Part 1: Typical migrations

1. The stories of four different migrations

2. Types of migrations

Part 2: Executing a migration

3. Preparation

4. Pre-migration

5. The migration

6. After the migration

7. The migration’s long-tail

8. A migration checklist

Part 3: The people and the business side of migrations

9. The people aspect of migrations

10. Selling migrations to the business

11. Closing advice for migrations

12. Further reading