Part 8 of Building Instagram's Authentication Backend . If you're just joining, the repo is here and you can catch the earlier parts on the YouTube playlist . We built an engine with no ignition Here's where we actually stood after seven parts of this series. We had a fully working AuthService — register, login, refresh, the works. We had a security layer sitting on top of it, filtering every request, deciding who's allowed where. We had entities, repositories, DTOs, a whole exception-handling backbone. And none of it had a URL. Not one line of that code could be reached from outside the JVM. No curl command, no Postman request, nothing. It's a strange feeling to have written that much working logic and still not be able to actually call any of it. So that's what this part is about — wiring up the front door. The controller, and why it's boring on purpose Here's the register endpoint, in full: @PostMapping ( "/registe...
Spring Boot JPA Entities, Flyway Migrations & Spring Data Repositories — The Database Layer Done Right (Episode 5)
There is one line in almost every Spring Boot tutorial that runs flawlessly on your laptop and slowly corrupts your database in production: spring : jpa : hibernate : ddl-auto : update # works on your laptop, quietly rewrites prod With ddl-auto: update , Hibernate looks at your entities on every startup and alters the live schema to match them. No migration file. No version. No review. No rollback. Two developers add different fields, deploy in a different order, and now staging and production have quietly diverged — and the day one of those "updates" needs to drop a column, Hibernate will happily take your data with it. In Episode 5 of Building Instagram's Authentication Backend , we do the opposite. The database is not something Hibernate improvises at boot — it is a versioned artifact, checked into git, owned by Flyway . We build the persistence layer in three deliberate steps: the SQL migration , then the JPA entities , then the Spring Data r...
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