Browse categories
Explore
Fiverr Pro
English
$
USD
I will fix bugs and improve your java or python application
Mario Trappein
About this gig
I will investigate and fix a clearly defined bug in your Python or Java application. I will reproduce the issue, identify the cause, implement a focused fix, and explain what changed. This service is suitable for small, well-scoped bugs in existing projects. Please provide the relevant code, error message or reproduction steps, expected behavior, and your environment details. New features, complete applications, major refactoring, and projects without reproducible requirements require a custom offer.
Get to know Mario Trappein
Mario Trappein
Senior Software Developer, Java Python Golang
- FromGermany
- Member sinceSep 2026
Languages
German, English
Senior software developer helping startups and businesses build reliable, maintainable software. I specialize in Java, Python, Go (Golang), JavaScript and TypeScript, with hands-on experience in web development, REST APIs, databases, automation and scripting. I also work with software testing, CI/CD pipelines, Docker and modern software-development workflows. From bug fixes and optimization to complete backend services and integrations, I deliver clean code, clear communication and practical solutions tailored to your goals.
Other Software Development Services I Offer
FAQ
Can you fix any bug?
I focus on small, clearly defined bugs that can be reproduced in an existing Python or Java project. Larger changes, new features, and unclear issues may require a custom offer.
Do you need my whole project?
No. Please share only the relevant files or a minimal reproducible example whenever possible. Never include passwords, API keys, or confidential personal data.
