You will get I will fix React bugs, UI issues, and API integration problems
Project details
I’m a Senior Frontend Engineer with 15+ years of experience fixing bugs and issues in React applications used in production.
If your React app has UI glitches, broken components, console errors, or API integration problems, I will identify the root cause and deliver a clean, reliable fix.
I specialize in fixing:
• React rendering and component issues
• Broken UI behavior and state management bugs
• API integration problems (REST or GraphQL)
• Console errors, warnings, and runtime crashes
• Form handling and validation issues
• Performance problems and unnecessary re-renders
How I work:
1. Reproduce and diagnose the issue
2. Identify the exact root cause
3. Apply a clean, maintainable fix
4. Test across browsers and devices
5. Explain the fix and provide guidance
This service is ideal for quick frontend fixes, production bugs, or React issues blocking your users.
You’ll receive professional, production-quality fixes — not temporary patches.
If your React app has UI glitches, broken components, console errors, or API integration problems, I will identify the root cause and deliver a clean, reliable fix.
I specialize in fixing:
• React rendering and component issues
• Broken UI behavior and state management bugs
• API integration problems (REST or GraphQL)
• Console errors, warnings, and runtime crashes
• Form handling and validation issues
• Performance problems and unnecessary re-renders
How I work:
1. Reproduce and diagnose the issue
2. Identify the exact root cause
3. Apply a clean, maintainable fix
4. Test across browsers and devices
5. Explain the fix and provide guidance
This service is ideal for quick frontend fixes, production bugs, or React issues blocking your users.
You’ll receive professional, production-quality fixes — not temporary patches.
Programming Languages
HTML & CSS, JavaScript, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$60
|
Standard
$150
|
Advanced
$350
|
|---|---|---|---|
| Delivery Time | 2 days | 4 days | 7 days |
Number of Revisions | 1 | 2 | 3 |
Number of Pages | 0 | 0 | 0 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - | - | - |
Optional add-ons
You can add these on the next page.
Fast Delivery
+$40 - $120
Extra Bug Fix
(+ 1 Day)
+$50Frequently asked questions
About Cosmel
Senior Backend Engineer | FastAPI, Django, Rails, Node | API Debugging
Tres Rios, Costa Rica - 11:08 pm local time
I specialize in Python (FastAPI, Django), Ruby on Rails, Node.js, PostgreSQL, and AWS, with deep expertise in API design, debugging, backend optimization, and serverless/cloud deployments.
Clients hire me to:
• Fix backend bugs, performance issues, failing endpoints, and 500 errors
• Diagnose and resolve API issues in FastAPI, Django, Rails, or Node
• Build secure, scalable REST and GraphQL APIs from scratch
• Improve database performance and eliminate bottlenecks (PostgreSQL, Redis)
• Modernize backend systems and migrate workloads to AWS (Lambda, API Gateway, S3, RDS)
• Develop automation, background workers, and distributed systems
• Add new backend features, integrations, and complex logic
Why technical teams trust me:
• I identify root causes quickly and fix them cleanly
• I understand real-world production systems and edge cases
• I write maintainable, well-tested code that survives scale
• I communicate clearly, give proactive updates, and deliver on time
• I reduce risk — no breaking changes, no surprises
Why Work With Me
• 15+ years experience across backend, APIs, architecture, and debugging
• Production-grade solutions, not “quick patches”
• Clear communication and expectations
• Strong ownership and delivery on deadlines
• Experience working with U.S. companies and distributed teams
• Ability to quickly understand existing systems and ship reliable results
Tech Stack
Python, FastAPI, Django, Node.js, TypeScript, Ruby on Rails
PostgreSQL, Redis
AWS Lambda, API Gateway, S3, RDS, CloudFront
REST, GraphQL, CI/CD, Docker
If you need a backend engineer who can take ownership, solve difficult problems, and deliver production-ready APIs and backend systems — let’s talk.
Steps for completing your project
After purchasing the project, send requirements so Cosmel can start the project.
Delivery time starts when Cosmel receives requirements from you.
Cosmel works on your project following the steps below.
Revisions may occur after the delivery date.
Analyze the reported issue
I will review your bug reported, inspect code, replicate the issue, and identify the root cause.
Fix and test the bug
I will apply a clean fix, test thoroughly, and ensure the issue is completely resolved.