I will fix bugs and develop rest apis in java spring boot


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Hi, I'm a backend developer with 10 years of experience in Java and Spring Boot.
I help businesses fix bugs, build REST APIs, and ship features fast.
WHAT I CAN DO:
Fix bugs in your existing Spring Boot project
Build new REST APIs (CRUD, auth, file upload, payment)
Database design & optimization (MySQL, PostgreSQL, Redis)
Integrate third-party APIs (Stripe, PayPal, SMS, OAuth)
MyBatis / JPA / Hibernate
JWT authentication, role-based access
Excel import/export (large dataset, formula, multi-sheet)
Performance tuning (slow SQL, N+1, caching)
WHY ME:
10+ years building production systems (e-commerce, CRM, BI dashboards)
Clean, documented code you can maintain
Fast reply within a few hours (GMT+8)
Free 7-day post-delivery support
WORK PROCESS:
1. You describe the bug or feature
2. I review your code/requirements and quote
3. I fix/develop and send you a working version
4. Free revision until you're happy
Please message me BEFORE ordering so I can confirm scope and timeline.
Let's ship it!
Conoce a Fengquan Xian
Senior Java Spring Boot Developer specializing in Payment and Web3
- DeChina
- Miembro desdejun 2026
Idiomas
Chino, Inglés
FAQ
Do you work with Spring Boot 2.x or 3.x?
Both. I'm comfortable migrating projects from 2.x to 3.x as well.
Can you work on my existing codebase?
Yes. Please share the repo (GitHub/GitLab/zip) along with setup instructions.
What if the bug is harder than expected?
I'll let you know within 24 hours after reviewing your code. We can adjust the package or split into milestones.
Do you provide source code?
Yes, full source code is delivered. You own it 100%.
Do you sign NDA?
Yes, happy to sign before reviewing any sensitive code.
What time zone are you in?
GMT+8 (Asia). I usually reply within 2-4 hours during my daytime, and within 12 hours otherwise.
