API Integration

I connect your web app to the services it depends on, and I build the APIs that mobile apps and other systems use to talk to it. That covers payment gateways such as Stripe, SMS and email through Twilio, Google Calendar, Firebase push notifications and custom REST APIs, written in Laravel or Node.js.

Integrations are where small mistakes cost real money: a payment charged twice, a notification that never arrives, an access token that expires and nobody notices. I'm a full stack developer in Pakistan who has run these integrations in live systems, and I build them to fail safely and to tell you when something goes wrong. Tell me which service you need to connect through the contact form, and I'll explain how I'd approach it.

Integrations I build

• Payments: Stripe and other payment gateways, including checkout, refunds and failed-payment handling.
• Messaging: Twilio SMS and email alerts.
• Scheduling: Google Calendar API, including automatic event creation and registration.
• Push notifications through Firebase Cloud Messaging.
• Reporting: Google Analytics 4 and Search Console data pulled into an admin dashboard.
• Your own REST API, for a mobile app, a React front end or outside partners.
• Any other service with a documented API.

What these integrations have done

• At Sublime Logics, payment gateway work raised the payment success rate by 15%, and Twilio SMS and email alerts lifted client response rates by 20%.
• For Makers Asylum, a Google Calendar API integration registered people automatically and cut registration errors by 80% and onboarding time by 30%.
• On a government-scale Laravel system at NITB, I added real-time notifications through Firebase Cloud Messaging, behind role-based access for several departments.
• On the Google Analytics annotations manager, I built the Laravel APIs with Passport authentication and the email system.
• This website's admin dashboard reads Google Analytics 4 and Search Console through their APIs, with a searchable query table and Excel export.

How I build an integration

• I read the provider's documentation and test against its sandbox first. For Stripe that means test mode, and I use Postman or Insomnia to check each call.
• Keys and secrets stay in environment configuration, never in the code or the repository.
• Slow or unreliable calls run in queued jobs, so a delay at the provider doesn't slow your pages. Failures are retried and logged.
• Payment and webhook events are checked for authenticity before the app acts on them.
• Automated Pest tests use fake responses, so the integration can be checked without touching the live service.
• You get a short written guide to every endpoint and setting.

REST APIs for your own app

If you need an API of your own, I build it in Laravel with Passport authentication, or in Node.js and Express.js with JWT. It has consistent JSON responses, validation, pagination and role-based access, so a mobile app or React front end can rely on it. My open source MERN stack agile board is an example of a REST API with token login, file uploads and a React client. If the API is part of a bigger build, it fits inside full stack web development.

Integrations that are already broken

• Payments that fail, duplicate or never update the order
• SMS or email that stops sending
• Google or other OAuth connections that expire
• An integration that works locally but fails in production, often because of server, SSL or firewall settings
• Pages that slow down because an API call runs in the middle of the request

I fix these under maintenance and bug fixing. If the problem is the server itself, see server deployment.

How to get started

1. Tell me which service you need to connect and what should happen when it works.
2. I review the provider's documentation and give you an estimate.
3. I build it in a sandbox or staging environment, and you check it before it touches real data. Please don't send live secret keys in a message. I'll set them up directly on your server.
4. I go live with you, hand over the guide and watch the first real transactions.

Paid work runs through Upwork, which protects payment for both of us.

Tell me what you need connected

Use the contact form or message me on Upwork. I reply within 24 hours. You can see more of my work on the portfolio page, or read about me.