I will build secure spring boot rest apis and backend services

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siyu_backend
Siyu Ren

About this gig

Need a focused Spring Boot backend that is clear, maintainable, and protected by explicit access rules?


I build Java REST APIs and backend modules with validation, consistent error handling, database access, transactional business logic, JWT authentication, role-based access, ownership checks, and focused tests.


Depending on the package, I can work with MyBatis or MyBatis-Plus, MySQL or PostgreSQL, database migrations, API documentation, Docker packaging, and one agreed integration.


My self-built food-ordering case demonstrates server-side price checks, atomic stock deduction, transactional order creation, single-instance idempotency, fulfillment logic, and rejection-path tests. I also have experience extending larger multi-module Spring Boot systems.


Each order is limited by an agreed endpoint list, data model, role matrix, and acceptance criteria. Frontend work, OAuth2 or SSO, payments, Kubernetes, high availability, security audits, and unreviewed full platforms are not included by default.


Please message me before ordering with your Java and Spring Boot versions, endpoint list, database, roles, and expected delivery.

Get to know Siyu Ren

Siyu Ren

AI App Troubleshooting and Backend Developer

  • FromChina
  • Member sinceJul 2026
  • Avg. response time1 hour
  • Languages

    Chinese, English
I help founders rescue and stabilize AI-built web apps and backend systems. I diagnose deployment failures, Supabase Auth/RLS problems, API and database bugs, and Spring Boot issues, then deliver tested fixes with clear handover notes. My stack includes Lovable, Bolt, Replit, React, Vite, Supabase, Vercel, Java, Spring Boot, REST APIs, PostgreSQL, MySQL, Redis, and n8n. With 8 years of backend experience, I focus on root-cause analysis, secure access, clear scope, and practical fixes without unnecessary rebuilding.

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