Handle Duplicate Email | Why 409 Exists – Here’s the Truth

00:00 Intro — handling duplicate email scenario
00:14 Service code setup in CustomerService
00:38 Extract email from request payload
01:06 Repository lookup by email
01:24 Throw exception: same email used with different data
01:52 Postman setup — preparing duplicate email test
02:20 Triggering unique constraint error (first run)
03:03 Debugging the mistake in code
03:26 Fixing repository call to use findByEmail
03:42 Retesting — receiving 409 Conflict response
04:00 Validating error message: “Same email ID used with different data”
04:07 Wrapping up duplicate email handling
04:24 Next steps — KYC status update feature preview


Sodelic Link - https://app.sodelic.com/p/B90z9kGqLPX...


In this video, we’ll implement duplicate email validation in our Customer Service.

You’ll learn:

Why duplicate emails must be rejected in banking apps

How to return the right HTTP status code (409 Conflict)

Spring Boot + JPA unique constraints for clean data

Real-world error handling best practices for microservices