You will get fix Java/Spring Boot API errors & backend bugs (auth, 400–500)
Project details
I will help you fix bugs, errors, and broken features in your Java/Spring Boot application quickly and professionally.
As a backend developer experienced in API development, authentication (JWT), database integration, and debugging, I focus on identifying the root cause and delivering clean, stable fixes.
You will receive clear communication, well-structured code, and solutions that don’t break the rest of your system.
My goal is to help you restore functionality fast and improve the overall performance of your application.
This service is perfect for API issues, CORS errors, authentication failures, unexpected exceptions, or any backend bugs that slow your project down.
As a backend developer experienced in API development, authentication (JWT), database integration, and debugging, I focus on identifying the root cause and delivering clean, stable fixes.
You will receive clear communication, well-structured code, and solutions that don’t break the rest of your system.
My goal is to help you restore functionality fast and improve the overall performance of your application.
This service is perfect for API issues, CORS errors, authentication failures, unexpected exceptions, or any backend bugs that slow your project down.
Programming Languages
HTML & CSS, JavaScript, JavaCoding Expertise
Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$20
|
Standard
$40
|
Advanced
$70
|
|---|---|---|---|
| Delivery Time | 2 days | 3 days | 4 days |
Number of Revisions | 1 | 2 | 3 |
Bug Investigation | |||
Fix Documentation | |||
Detailed Code Comments | - |
Optional add-ons
You can add these on the next page.
Fast Delivery
+$10 - $20
Additional Revision
+$10
Detailed Code Comments
(+ 1 Day)
+$10Frequently asked questions
About Khanittha
Java Spring Boot Developer | API Errors Fix | Debugging | Performance
Chiang Rai, Thailand - 12:35 pm local time
I help clients with:
✔ Fixing Spring Boot errors & exceptions
✔ Debugging REST APIs (400, 401, 403, 500 issues)
✔ Repairing JWT/OAuth2 authentication
✔ Solving CORS, routing, and request/response bugs
✔ Improving backend logic & performance
✔ Cleaning/optimizing existing code (monolithic or microservices)
Why clients trust me:
Clear communication
Fast and reliable bug fixing
Clean, maintainable code
Strong debugging ability (root-cause analysis)
Flexible with small tasks, short-term contracts, and long-term support
Based in Thailand, preparing to relocate to Germany — available worldwide for remote work.
Steps for completing your project
After purchasing the project, send requirements so Khanittha can start the project.
Delivery time starts when Khanittha receives requirements from you.
Khanittha works on your project following the steps below.
Revisions may occur after the delivery date.
Investigation & debugging
I analyze the code, reproduce the issue, and identify the root cause of the bug.
Apply fixes + testing
I fix the issue, test it thoroughly, and ensure it doesn’t impact other parts of your system.