You will get a working fix for your Python, FastAPI, or LLM application
Project details
Having trouble with a Python app, a FastAPI endpoint, or an LLM integration?
I can take a look at the issue, reproduce it, find the root cause, and apply a clean fix without making unnecessary changes to the rest of your project.
I can help with Python errors, FastAPI problems, broken API integrations, authentication issues, async or streaming bugs, configuration problems, and errors in LLM-based applications.
Once the work is complete, I will send you the updated code along with a short explanation of what caused the issue and what was changed.
This service is best suited for clearly defined debugging tasks. For larger features, full rewrites, or several unrelated issues, we can agree on a separate scope before moving forward.
I can take a look at the issue, reproduce it, find the root cause, and apply a clean fix without making unnecessary changes to the rest of your project.
I can help with Python errors, FastAPI problems, broken API integrations, authentication issues, async or streaming bugs, configuration problems, and errors in LLM-based applications.
Once the work is complete, I will send you the updated code along with a short explanation of what caused the issue and what was changed.
This service is best suited for clearly defined debugging tasks. For larger features, full rewrites, or several unrelated issues, we can agree on a separate scope before moving forward.
Programming Languages
PythonCoding Expertise
Performance OptimizationWhat's included
| Service Tiers |
Starter
$49
|
Standard
$119
|
Advanced
$249
|
|---|---|---|---|
| Delivery Time | 2 days | 3 days | 5 days |
Number of Revisions | 1 | 1 | 2 |
Bug Investigation | |||
Fix Documentation | - | ||
Detailed Code Comments | - | - |
Optional add-ons
You can add these on the next page.
Additional Revision
+$20
Deployment and configuration check
(+ 2 Days)
+$50Frequently asked questions
About Hasan
AI Engineer | Python, FastAPI, RAG & AI Agent Development
Bursa, Turkey - 6:05 am local time
I build end-to-end LLM applications using Python and FastAPI, with a focus on RAG systems, AI agents, API integrations, and reliable backend workflows.
I also develop production-ready Flutter applications using Dart, Firebase, and REST APIs, with two apps currently published on the App Store.
I can help you with:
• RAG chatbots connected to documents, websites, databases, or internal knowledge
• AI agents with tool calling, structured workflows, and external API integrations
• Multi-agent assistant systems and agent orchestration
• FastAPI backends, REST APIs, streaming responses, and asynchronous workflows
• OpenAI, Gemini, Claude, and other LLM API integrations
• Prompt engineering, context design, and hallucination reduction
• Debugging and improving existing Python, FastAPI, or LLM applications
• Model evaluation based on accuracy, latency, reliability, and cost
• Full-stack AI product integration using React and Node.js when required
• Docker, Linux, database, authentication, and deployment preparation
Relevant experience:
• Designed and implemented a multi-tenant RAG-based multi-agent assistant with knowledge retrieval, tool calling, streaming responses, live-support handoff, and tenant isolation.
• Built backend and full-stack systems connecting APIs, databases, authentication, dashboards, and real-time workflows.
• Improved LLM workflows through retrieval optimization, prompt and context engineering, output evaluation, and error handling.
• Worked with existing codebases to troubleshoot issues, add features, and prepare applications for reliable public use.
What you can expect when working with me:
• Clear and responsive communication
• Quick understanding of existing codebases and project requirements
• Clean, maintainable, and documented code
• Honest estimates and clearly defined deliverables
• Regular progress updates and reliable delivery
• More than 30 hours of weekly availability
You can send me your requirements, current codebase, or technical problem. I will review the situation and recommend the clearest path toward a working solution.
Steps for completing your project
After purchasing the project, send requirements so Hasan can start the project.
Delivery time starts when Hasan receives requirements from you.
Hasan works on your project following the steps below.
Revisions may occur after the delivery date.
Issue reproduction and diagnosis
I will review the code, logs, environment details, and reproduction steps to confirm the issue and identify its root cause.
Fix implementation
I will implement the agreed fix while preserving the existing project structure and avoiding unnecessary changes.