The text discusses the challenges of making changes to a database schema, particularly when adding unique constraints or enforcing NOT NULL values. These operations can lead to unexpected locking issues, causing downtime and outages. The article highlights the importance of caution and expertise in managing database schema migrations. It introduces two tools, Atlas and Neon, which can help mitigate these risks. Atlas provides static analysis to catch risky migrations before they reach production, while Neon enables realistic pre-deployment simulations using database branching. By integrating these tools into a CI/CD pipeline, developers can prevent database locks from taking down their application, embracing schema migrations with confidence.