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Fiverr Pro
English
$
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I will fix bugs or add features to your node application or API
Serhii L.
About this gig
Need help with a Node.js backend, API, or an existing backend codebase?
Im a Software Engineer with 8+ years of experience building and maintaining web applications and backend services. I can help fix existing issues, build new API endpoints, add backend features, or improve your current implementation without unnecessary rewrites.
What I can help with:
- Build or fix REST APIs and API endpoints
- Node.js / TypeScript backend development
- Database integration with PostgreSQL and complex queries
- Authentication, authorization & third-party integrations
- Turn AI-generated code into production-ready software
- Refactor backend code for performance, scalability & maintainability
- Connect and extend frontend applications with backend services
- AI and external API integrations
Why work with me?
I focus on understanding the existing codebase first and delivering reliable, maintainable solutions rather than introducing unnecessary complexity.
If your task requires changes across the frontend, backend, API, or database, I can handle the full feature instead of treating the backend in isolation.
Have a specific problem? Message me before ordering and I'll review what needs to be done.
Get to know Serhii L.
Serhii L.
Software Engineer specializing in Web and Mobile
- FromUkraine
- Member sinceApr 2026
- Avg. response time1 hour
Languages
Ukrainian, English
Software Engineer specializing in web and mobile development, with 8+ years of experience building reliable software and solving real product problems.
I value clean code, thoughtful architecture, scalability, and long-term maintainability. Experienced with different technologies and approaches to find the right solution for each business problem, making the most of AI where it adds value while keeping things simple and reliable.
I can help build web and mobile products, improve existing applications, develop APIs and backend services, solve technical issues, and provide technical guidance.
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FAQ
Can you review my project before I place an order?
Yes. Feel free to contact me before placing an order. I can review your requirements and, when needed, look at the relevant parts of your codebase to understand the issue, determine the scope, and provide a clear price before we start. The initial discussion and assessment are free.
Can we have a call to discuss the project?
Absolutely. For complex or unclear requirements, we can arrange a quick Google Meet call so you can explain the issue, show me what you need, and discuss the expected result.
Can you fix AI-generated code?
Yes. I can fix and refactor code generated by Cursor, Claude, ChatGPT, Lovable, Bolt, v0, and similar AI tools, helping turn AI-generated MVPs into reliable, production-ready software.
Do you only work on the backend?
No. If solving the problem requires changes to the frontend, database, or other parts of the application, I can handle them as part of the solution.
What do you need from me to get started?
Usually, I need a description of the issue or feature, access to the relevant code or repository, and any information needed to reproduce the issue or understand the expected result.
Can you integrate third-party APIs?
Yes. I can integrate external APIs and services into your backend or existing application.
Can you work with databases?
Yes. I can work with PostgreSQL and handle database queries, schema changes, ORM integration, etc.
