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I will fix bugs and debug your javascript or java application
Felix G
About this gig
Stuck with an error you can't solve? I'll find the root cause and fix bugs in your JavaScript, Node.js or Java application. I'm a senior software developer with 6+ years building and maintaining banking and mobile apps, so I'm used to debugging complex production issues.
What I can fix:
- Runtime errors, crashes and unexpected behavior
- Broken API calls, integrations and data flow issues
- Backend errors in Node.js, Express, Java or Spring
- Database query problems and slow performance
- Logic bugs and edge cases
How I work: I reproduce the problem, find the root cause, apply a clean fix and test it. You'll get the corrected code and a clear explanation of what was wrong, so it doesn't happen again.
Please message me before ordering with the error message and a short description, so I can confirm I can help.
Get to know Felix G
Felix G
Senior Software Developer for Digital Banking APIs and Mobile Apps
- FromUnited States
- Member sinceOct 2026
- Avg. response time1 hour
Languages
Spanish, English
Senior software developer with 6+ years building digital banking solutions and mobile apps. I specialize in API and third-party service integration, backend development in JavaScript and Java, digital wallet integration, and fraud prevention services. Experienced with Temenos Infinity, REST APIs, JSON, SQL, Firebase Analytics, and Feature Flags. I analyze requirements, fix complex defects, and optimize performance and stability. I can help you integrate APIs, build or improve backend services, and deliver reliable mobile banking features.
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FAQ
What if you can't fix the bug?
I review the issue before you order. If I can't fix it after starting, I'll explain what I found and we can cancel the order.
What do you need from me?
The error message or a description of the bug, steps to reproduce it, and access to the code (repository or files). Logs and screenshots help too.
Will you explain what caused the bug?
Yes. Every fix includes a short explanation. Standard and Premium also include a root cause analysis, and Premium adds a written report.
