You will get a production-ready React or Supabase app with critical bugs fixed
Project details
If your React, TypeScript, Supabase, or AI-generated web app looks complete but a critical workflow still fails, I can turn it from a fragile prototype into a verified, production-ready result.
I independently build and operate full-stack SaaS, AI, payment, and real-time data systems. My work covers frontend and backend debugging, Supabase Auth and PostgreSQL, API integrations, Stripe workflows, FastAPI services, testing, deployment, logging, and production handoff.
This service is designed for focused engineering outcomes: one critical defect, one broken end-to-end workflow, or a clearly bounded set of related stability issues. I begin by reproducing the problem and identifying the root cause, then implement the repair, verify the affected flow, and document exactly what changed.
You receive clean, maintainable code, evidence that the agreed workflow works, and clear English handoff notes. Scope, deliverables, timeline, and acceptance criteria remain explicit throughout the project.
Please message me before purchasing if the app cannot run, the source code is unavailable, or it involves a full rebuild, complex payment custody, regulated data, or an unknown legacy system.
I independently build and operate full-stack SaaS, AI, payment, and real-time data systems. My work covers frontend and backend debugging, Supabase Auth and PostgreSQL, API integrations, Stripe workflows, FastAPI services, testing, deployment, logging, and production handoff.
This service is designed for focused engineering outcomes: one critical defect, one broken end-to-end workflow, or a clearly bounded set of related stability issues. I begin by reproducing the problem and identifying the root cause, then implement the repair, verify the affected flow, and document exactly what changed.
You receive clean, maintainable code, evidence that the agreed workflow works, and clear English handoff notes. Scope, deliverables, timeline, and acceptance criteria remain explicit throughout the project.
Please message me before purchasing if the app cannot run, the source code is unavailable, or it involves a full rebuild, complex payment custody, regulated data, or an unknown legacy system.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$350
|
Standard
$750
|
Advanced
$1,350
|
|---|---|---|---|
| Delivery Time | 3 days | 5 days | 8 days |
Number of Revisions | 1 | 2 | 2 |
Bug Investigation | |||
Fix Documentation | |||
Detailed Code Comments |
Frequently asked questions
About Luyuan
Full-Stack & AI Developer | Data Pipelines, Python, Next.js, Supabase
Shanghai, China - 8:57 pm local time
Much of my work involves systems where a mistake does not announce itself: a feed goes quiet, a provider renames a field, the same record arrives twice, an export is keyed on the wrong identifier and gets rejected by someone else's system while everything looks fine locally. Those are the cases I design for first.
What I can deliver:
• Complete products end to end — Next.js, React, TypeScript, Python, FastAPI, PostgreSQL and Supabase
• Data ingestion and reconciliation — third-party APIs, scheduled jobs, deduplication, backfill, and alerting when a source goes quiet
• AI inside the product rather than around it — OpenAI, Claude and Gemini behind a server-side interface, with keys that never reach the browser
• Payments and access control — Stripe checkout, subscriptions, webhooks, roles and multi-tenant boundaries
• Testing, deployment, documentation and handover written for the next developer
Recent work, all my own and all still running: a multilingual AI SaaS product on React, TypeScript and Postgres that I designed, built, deployed and still operate; a production Next.js company website; and automated trading systems in Python that ingest market feeds, reconcile against the source on restart, and emit orders keyed to the venue's own instrument identifiers.
I work on clearly scoped fixed-price projects with written deliverables and acceptance criteria. You will know what is included, what it costs, and what “done” means before development begins.
I split my time between China and Canada, keep reliable overlap with North American business hours, and send written updates throughout the project.
Steps for completing your project
After purchasing the project, send requirements so Luyuan can start the project.
Delivery time starts when Luyuan receives requirements from you.
Luyuan works on your project following the steps below.
Revisions may occur after the delivery date.
Reproduce and isolate the failure
I reproduce the issue, inspect the relevant code path, and confirm the root cause and repair boundary.
Implement and verify the fix
I implement the agreed repair, add appropriate error handling, and verify the affected workflow with focused tests.