You will get Fix your API integration, webhook, CSV, or data sync failure with proof
Project details
Are records missing, duplicated, rejected, or mapped to the wrong fields? I trace one bounded REST API, webhook, CSV, or data-sync failure in Mock, Sandbox, or Staging, repair the responsible boundary, and verify it with a repeatable test plus reconciliation counts.
Choose a diagnostic when the boundary is uncertain, a standard rescue for one bounded failure, or the reliability sprint for up to two directly related failures in the same data flow. Relevant scope may include authentication or signing, field mapping, pagination, retries, idempotency, duplicate handling, or error reporting.
You receive failure evidence, root-cause findings, the minimal reviewable change, a repeatable contract or integration test, replay instructions or fixture, input/success/failure/duplicate counts, reconciliation results, changed files and commands, and rollback notes. Production credentials, unapproved production writes, unrelated systems, mass migration, and open-ended integration work are excluded.
Choose a diagnostic when the boundary is uncertain, a standard rescue for one bounded failure, or the reliability sprint for up to two directly related failures in the same data flow. Relevant scope may include authentication or signing, field mapping, pagination, retries, idempotency, duplicate handling, or error reporting.
You receive failure evidence, root-cause findings, the minimal reviewable change, a repeatable contract or integration test, replay instructions or fixture, input/success/failure/duplicate counts, reconciliation results, changed files and commands, and rollback notes. Production credentials, unapproved production writes, unrelated systems, mass migration, and open-ended integration work are excluded.
Database Type
MySQL, PostgreSQLWhat's included
| Service Tiers |
Starter
$79
|
Standard
$349
|
Advanced
$649
|
|---|---|---|---|
| Delivery Time | 1 day | 4 days | 5 days |
Number of Revisions | 1 | 1 | 2 |
Source Code | - |
Frequently asked questions
About Kaiwei
SaaS Bug Fixes, API Integrations & Docker Deployments
Yichun, China - 8:04 am local time
I help small SaaS teams with:
• Next.js, React, Node.js, Supabase auth/RLS, and launch-blocking bugs
• REST APIs, webhooks, CSV/data sync, field mapping, retries, and duplicate or missing records
• Docker, NGINX, Linux, and staging deployment troubleshooting
• Java/Spring Boot and PostgreSQL integration issues
My approach is simple: reproduce the failure, isolate the root cause, make the smallest safe change, test the critical path, and document validation and rollback steps.
Best fit: an existing codebase, one clear blocker, a staging or sandbox environment, and an objective acceptance criterion. I work through clear written, asynchronous communication and keep scope, risks, and deliverables explicit.
Steps for completing your project
After purchasing the project, send requirements so Kaiwei can start the project.
Delivery time starts when Kaiwei receives requirements from you.
Kaiwei works on your project following the steps below.
Revisions may occur after the delivery date.
Data contract and scope lock
Confirm the source, target, authorized fields, expected record behavior, one bounded failure, sanitized fixture, and objective acceptance or reconciliation counts.
Minimal integration repair
Reproduce the failure in Mock, Sandbox, or Staging and change only the agreed authentication, mapping, pagination, retry, idempotency, or error-handling boundary.