You will get Custom REST API Integration & Backend Automation
Project details
Need to connect your system to Stripe, Amazon, Shopify, ERP, or any external API?
I implement secure, production-ready backend integrations designed for reliability, scalability, and long-term maintainability.
This service is ideal for:
• SaaS platforms
• E-commerce systems
• Marketplaces
• ERP / CRM integrations
• Payment & webhook-based systems
• Custom backend automation
What You Get
✔ Secure third-party API integration
✔ OAuth 2.0 / API key authentication
✔ Webhook subscription & verification
✔ Retry logic & rate limit handling
✔ Data transformation & sync automation
✔ Error logging & monitoring setup
✔ Clean, maintainable backend structure
I focus on backend-first architecture — not quick patches.
I implement secure, production-ready backend integrations designed for reliability, scalability, and long-term maintainability.
This service is ideal for:
• SaaS platforms
• E-commerce systems
• Marketplaces
• ERP / CRM integrations
• Payment & webhook-based systems
• Custom backend automation
What You Get
✔ Secure third-party API integration
✔ OAuth 2.0 / API key authentication
✔ Webhook subscription & verification
✔ Retry logic & rate limit handling
✔ Data transformation & sync automation
✔ Error logging & monitoring setup
✔ Clean, maintainable backend structure
I focus on backend-first architecture — not quick patches.
Programming Languages
PHP, HTML & CSS, JavaScriptCoding Expertise
Cross Browser & Device Compatibility, Localization, Performance OptimizationWhat's included
| Service Tiers |
Starter
$450
|
Standard
$950
|
Advanced
$1,990
|
|---|---|---|---|
| Delivery Time | 2 days | 4 days | 7 days |
Number of Revisions | 1 | 2 | 3 |
Number of Pages | 0 | 0 | 0 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code |
Optional add-ons
You can add these on the next page.
Fast Delivery
+$100 - $300
Add a second API
(+ 2 Days)
+$120
47 reviews
(37)
(6)
(1)
(1)
(2)
This project doesn't have any reviews.
ta
tony a.
Apr 9, 2026
update?
Great service wonderful work always happy with this team. Good work. I will use you again.
ta
tony a.
Mar 18, 2026
Coding and Wordpress
Amazing experience every time! Very skilled, communicates well, and always delivers great work. I’ve used this seller multiple times and will continue to do so. Don’t let a few bad reviews fool you—this is someone who really cares about their clients.
ta
tony a.
Mar 14, 2025
You will get professional website with great features and look
Great job don’t look else where
MD
MD SAZID HASAN D.
Oct 9, 2024
Amazon Selling Partner API(for reports only) Postman Collection Setup for Japan Marketplace
A job well done!! And pretty fast!!
AR
Abdul R.
Sep 20, 2024
Stripe API Fix and Laravel Socket Integration
I am disappointed with this developer's performance. A 15-day project extended to nearly 3 months without completion. They struggled with small fixes, were often unresponsive, and frequently asked irrelevant questions. Despite multiple attempts to guide them, they failed to deliver the expected results and continuously requested payment before any significant progress.
About Hafiz Muhammad
Software Architect & Backend Engineer | Payments, ERP, APIs | 22+ Yrs
100%
Job Success
Multan, Pakistan - 6:20 am local time
I've shipped 50+ platforms — a government compliance system
for 5,000+ Pakistan Railways employees (World Bank-audited),
an AI module that cut manual data entry by 85%, FinTech
backends handling payments across UK, UAE and Europe, and
a YouTube-style video platform with WebRTC real-time chat
serving thousands of concurrent users.
If you need someone to write a feature and disappear, I'm
not the right fit. If you need someone who thinks about
schema design, security, query performance, and what happens
at 3x your current load — that's exactly what I do.
━━ WHAT I BUILD WELL ━━
► FinTech & Payment Systems
Built complete payment ecosystems including Stripe Connect onboarding, subscriptions, creator payouts, webhook orchestration, payment abstraction layers, and multi-provider payment integrations (Stripe, Wise, Payoneer, JazzCash, EasyPaisa).
► Backend Architecture (Node.js / Laravel / NestJS)
Designed scalable RESTful and GraphQL APIs with optimized PostgreSQL queries, Redis caching, and clean service boundaries for high-performance enterprise applications
► PostgreSQL at Scale
Schema design, migration strategies, index optimisation.
I reduced a government system's query time from 15 seconds
to 200ms. Connection pooling, partitioning, full audit
logging for compliance.
► AI / OpenAI API Integration
Production AI systems using OpenAI GPT-4/4o with OCR, intelligent document processing, provider-agnostic architecture, prompt versioning, structured outputs, and enterprise workflow automation.
► Security & Compliance
JWT with refresh rotation, RBAC, OAuth 2.0, audit trails.
Passed World Bank security audit for a public-sector system.
I treat security as architecture, not a checkbox.
► Amazon SP-API / Shopify / E-commerce
Japanese marketplace integration, multi-vendor fulfilment
platforms, rate limit management, exponential backoff.
Real resilience patterns, not optimistic code.
► WordPress & WooCommerce (Custom & Complex)
Multi-vendor WooCommerce platforms with custom commission
logic, AJAX cart systems, ACF Pro integrations, and vendor
dashboards. WP Rocket + Cloudflare configuration. Custom
PHP plugins, payment gateway integration (Stripe, PayPal,
JazzCash), and performance optimization for high-traffic
stores. I debug codebases I didn't write — fast.
━━ PAST ENGAGEMENTS ━━
• Pakistan Railways (2021–2023) — Audit & Fuel Management
systems for 5,000+ staff. World Bank compliance. Query
optimisation: 15s → 200ms.
• YetiScanner AI (2024) — OpenAI GPT-4 document processing
for YetiForce CRM (Netherlands). 85% reduction in manual
invoice entry.
• Global Connect ERP (Bahrain, 2024–2025) — Oracle monolith
→ PostgreSQL microservices. 3× performance improvement.
• Ourstube Media (2025–present) — YouTube-style platform:
Node.js microservices, WebRTC, custom AdTech, 4-provider
payment abstraction. 60% faster video processing via CDN.
• Thread Production ERP (2024) — Multi-tenant Laravel 11
system for textile manufacturing. Complex RBAC across
multiple facilities.
━━ STACK ━━
Node.js · TypeScript · NestJS · Express
Laravel (5–11) · PHP
PostgreSQL · MySQL · MongoDB · Redis · Oracle
AWS (EC2, S3, RDS, Lambda, CloudWatch), Docker, Redis, Grafana, GitHub Actions
OpenAI API · WebRTC · WebSockets
Stripe · Twilio Voice · Twilio Functions · SendGrid · Shopify API · Amazon SP-API · WooCommerce
━━ HOW I WORK ━━
I take a small number of engagements at a time so I can
give each one proper attention. I communicate daily, push
working code early, and flag risks before they become
problems. Timezone: PKT (UTC+5) — available for UK, UAE
and European business hours with overlap.
Whether you need it built, or need an architect to validate the plan and pressure-test the decisions before you build — that's work I do. If your project involves backend architecture, payment systems, AI integration, database performance, ERP/systems integration, or taking a messy codebase and making it production-ready, send me a message with what you're building. I'll tell you honestly if I'm the right person for it.
Steps for completing your project
After purchasing the project, send requirements so Hafiz Muhammad can start the project.
Delivery time starts when Hafiz Muhammad receives requirements from you.
Hafiz Muhammad works on your project following the steps below.
Revisions may occur after the delivery date.
Architecture Review
Review API documentation and define integration structure.
Secure Integration Setup
Implement authentication, endpoints, and webhook logic.