Plan NoSQL schema changes so Clojure readers, writers, and migration jobs can coexist safely.
This section bridges the chapter overview and the detailed lessons below. For Java engineers, the practical question is how to handle schema evolution in Clojure NoSQL systems in Clojure code at the database boundary.
| Review focus | What to check |
|---|---|
| Readers | Handle old and new shapes without brittle conditionals. |
| Writers | Version writes deliberately as the model changes. |
| Migrations | Use Clojure transformations for repeatable backfills. |
Use the child lessons to move from concept to implementation. The section goal is to make the trade-off visible before the code hardens around a database assumption.