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$
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I will fix bugs and errors in your java spring boot backend
Mahathir
About this gig
I am a backend engineer with 3+ years building production Java and
Spring Boot systems for fintech, telecom and ERP companies.
If your Spring Boot app is throwing errors, returning wrong data, or
failing in production, send me the details and I will find out why.
START HERE
Message me with your error before you order. I will tell you whether
I can fix it, and roughly what it will take. That costs you nothing.
If I cannot solve it, I will say so rather than waste your time.
WHAT I FIX
- Startup and configuration errors
- Broken REST and GraphQL APIs
- JPA / Hibernate mapping, lazy loading and N+1 problems
- Slow PostgreSQL and MySQL queries
- Transaction and concurrency bugs
- Spring Security and JWT authentic
- Kafka producer and consumer issues
- Docker build and deployment failu
SCOPE
Each package covers a set number of specific, reproducible bugs. I
need the source code and clear step.
Rewriting an application, bugs I cannot reproduce, and work on servers
or third-party accounts I do not co- message
me and I will quote it.
Get to know Mahathir
Mahathir
Backend Engineer
- FromBangladesh
- Member sinceSep 2026
Languages
Bengali, English, Hindi
Backend engineer with 3+ years building production Java and Spring Boot
systems for fintech, telecom and ERP companies.
I mostly fix and extend existing backends: broken REST and GraphQL APIs,
JPA/Hibernate mapping errors, slow PostgreSQL and MySQL queries,
transaction bugs, Kafka consumers, and Docker deployment failures.
I will tell you honestly if I cannot solve your problem, and I do not
disappear mid-project.
Send me your error message or repo link and I will tell you what is
wrong before you order.
FAQ
What do you need from me to get started?
The error message or a description of the wrong behaviour, steps to reproduce it, and access to the relevant code or repository. Your Java, Spring Boot and database versions help too.
Do I have to give you access to my whole project?
No. If you can isolate the relevant files or share a minimal reproducible example, that is usually enough. Full repo access just makes complex issues faster to solve.
What if you cannot fix the problem?
I will tell you before you order whether I think I can solve it. If I take the order and cannot deliver a fix, I will cancel it and refund you.
Do you work with older Spring Boot or Java versions?
Yes. I have worked with Java 8 through Java 21 and both Spring Boot 2 and 3, including legacy codebases.v
Can you add a new feature instead of fixing a bug?
Yes, message me first with the details and I will send you a custom offer with the right scope and price.
Will my code stay confidential?
Yes. I do not share, reuse or publish client code, and I am happy to sign an NDA before you send anything. I only need access to the parts of the project relevant to the bug.
What counts as one bug?
One reproducible problem with one root cause. If fixing it reveals a separate unrelated issue, I will tell you and quote it rather than silently expanding the work
Can you fix problems on my server or cloud account?
Code and configuration issues, yes. Anything needing direct access to your servers, cloud accounts or third-party services needs a custom offer, since access and risk are different from a normal code fix.
