You will get API Development & Integration | Stripe HubSpot OpenAI | Node.js
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Project details
Need Stripe payments, OpenAI integration, or a custom API built for your app? I have shipped 30+ API integrations across SaaS platforms, HealthTech systems, and marketplaces.
What I build:
→ Stripe payment integration with webhooks and subscription billing
→ OpenAI GPT-4 integration with prompt engineering and error handling
→ HubSpot, Salesforce, and CRM integrations with data sync
→ Google Calendar, Twilio, SendGrid, and third-party API connections
→ Custom REST and GraphQL APIs with JWT auth and documentation
→ Webhook architecture and real-time data pipelines
What's included:
→ Clean, documented code
→ API documentation (Swagger/OpenAPI)
→ Postman collection for testing
→ Security best practices (rate limiting, input validation)
→ Deployment to your server or cloud
Why me:
→ 30+ API integrations shipped in production
→ Stripe, OpenAI, HubSpot, HL7, Google Calendar — real integrations, not tutorials
→ I handle edge cases, retries, and error handling so your integration does not break at scale
Tell me what you need integrated. I will give you an accurate quote within a few hours.
What I build:
→ Stripe payment integration with webhooks and subscription billing
→ OpenAI GPT-4 integration with prompt engineering and error handling
→ HubSpot, Salesforce, and CRM integrations with data sync
→ Google Calendar, Twilio, SendGrid, and third-party API connections
→ Custom REST and GraphQL APIs with JWT auth and documentation
→ Webhook architecture and real-time data pipelines
What's included:
→ Clean, documented code
→ API documentation (Swagger/OpenAPI)
→ Postman collection for testing
→ Security best practices (rate limiting, input validation)
→ Deployment to your server or cloud
Why me:
→ 30+ API integrations shipped in production
→ Stripe, OpenAI, HubSpot, HL7, Google Calendar — real integrations, not tutorials
→ I handle edge cases, retries, and error handling so your integration does not break at scale
Tell me what you need integrated. I will give you an accurate quote within a few hours.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Localization, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$400
|
Standard
$1,000
|
Advanced
$2,500
|
|---|---|---|---|
| Delivery Time | 5 days | 14 days | 28 days |
Number of Revisions | 2 | 3 | 5 |
Number of Pages | 2 | 5 | 10 |
Design Customization | - | - | |
Content Upload | |||
Responsive Design | - | - | - |
Source Code |
Optional add-ons
You can add these on the next page.
Fast Delivery
+$75 - $350
Additional Revision
+$50
Additional Page
(+ 2 Days)
+$100Frequently asked questions
41 reviews
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(3)
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TS
Tim S.
Jun 13, 2026
Senior TypeScript / Next.js Engineer for Payments Integration & Go-Live (Existing Codebase)
Excellent developer. I engaged Waseem for the launch-critical payment, payout and identity integrations on my web platform and he delivered to a high standard throughout. Strong technical quality on a modern stack (TypeScript, Next.js, Prisma, Postgres), genuine attention to security, and real ownership of the work. Communication was clear, turnaround fast, and when I sent work back for a change he grasped the reason at once and fixed it properly. Reliable, fast, and careful with the parts that matter. Would gladly work with him again.
LT
Lets T.
Jun 12, 2026
QQQ Real-Time Trading Scanner Trial Build
This was my first time hiring on Upwork and I got lucky finding Waseem. I gave him a rough idea and he turned it into a real product, a Python system that watches real time data and sends alerts straight to my phone on Telegram with the exact numbers I need. Then he got the same thing running inside the platform I use every day, live the same week I asked. True full stack developer, servers, database, API connections, all handled on his own.
When I thought something was broken he didn't guess, he pulled the logs, showed me what happened and fixed it. He even cut my monthly hosting costs without me asking. The system has been running since launch and I have not had to touch it once. Thinks like an AI engineer, automates everything. First hire on here and he set the bar high, I already have more work lined up for him. Take him if he has an opening.
When I thought something was broken he didn't guess, he pulled the logs, showed me what happened and fixed it. He even cut my monthly hosting costs without me asking. The system has been running since launch and I have not had to touch it once. Thinks like an AI engineer, automates everything. First hire on here and he set the bar high, I already have more work lined up for him. Take him if he has an opening.
CR
Cameron R.
Jun 7, 2026
Full-Stack Developer to Build AI-Powered Sales Productivity Tool (HubSpot + G-Cal)
MS
Melanie S.
May 21, 2026
Solo Select — Security & Tenant-Isolation Review
Waseems communication was excellent and he delivered quickly. We are using him and his team now for another big project. He has been wonderful to deal with and has picked up on very complicated logic on a niche program very quickly.
CG
Chris G.
May 18, 2026
Full Stack Web Application Development
Waseem delivered cloud infrastructure work for our HealthTech platform that was clean, secure, and production-ready. He moved fast, communicated proactively, and stayed engaged well past the initial scope to support post-deployment refinements and edge-case fixes. Strong across AWS, Docker, Node, and Postgres and easy to work with when requirements shifted mid-build. Would hire again without hesitation. Highly recommended for any team that needs a serious full-stack engineer with healthcare-grade attention to detail.
About Waseem
Full Stack Developer & AI Engineer | SaaS MVPs, AI Agents & RAG
100%
Job Success
Bahawalpur, Pakistan - 6:45 pm local time
WHAT MAKES ME DIFFERENT
Most developers build exactly what you spec. You get someone who tells you what the business actually needs first, before you spend the budget, then builds it to last. Five plus years leading architecture, making build-versus-buy calls, and operating as fractional CTO for founders without a full-time technical hire. The rare part: shipped HIPAA-compliant healthcare systems and SEC-compliant fintech infrastructure to US standards, where audit trails and reliability are non-negotiable. Few AI developers can claim that honestly.
PROVEN IN PRODUCTION
The VP of Enterprise Solutions at Fukuda Denshi USA endorsed an HL7 gateway I built for their HealthMosaic platform, now moving 10,000+ clinical messages a day from 200+ hospital monitors at a 99% delivery rate, saving an estimated $400K a year. For a US fintech startup, a SEC Reg CF compliant backend with 248 passing tests and zero production bugs.
What clients say:
"He thinks like a product owner, not just a developer, and delivered production-ready work ahead of schedule." Justin R., VP of Enterprise Solutions, Fukuda Denshi USA
"By far the best developer I've worked with. If you need someone who delivers, hire him." Carmen M., Business Consultant
"Clean, well thought out design, finished weeks ahead of schedule." Jett S., Founder, NxtSzn
If you're building in AI, healthcare, fintech, or any SaaS where it has to work the first time, send me what you're building. You'll hear back within a day on whether I'm the right fit, and I'll tell you straight if I'm not.
WHAT I BUILD FOR YOU
→ AI-powered SaaS and MVPs, multi-tenant, Stripe billing, RBAC, row-level security, architected to scale from day one
→ AI agents, RAG systems, and intelligent automation on OpenAI, Claude, Gemini, and LangChain, built around your business logic, not wrapper demos
→ HIPAA-compliant healthtech, HL7, FHIR, EMR integration, clinical workflows to US standards
→ Fintech infrastructure, event-sourced ledgers, escrow, payments, audit-grade reliability
→ API and system integration, REST, GraphQL, webhooks, CRM and ERP, into existing and legacy codebases
→ Cloud and DevOps, AWS, Docker, CI/CD, production deployments that hold up under load
CORE STACK & KEYWORDS
React, Next.js, TypeScript, Node.js, NestJS, Python, FastAPI, Django · OpenAI, Anthropic Claude, Google Gemini, LangChain, RAG, pgvector, Pinecone, AI agents · PostgreSQL, MongoDB, Redis, Prisma, Supabase, Firebase · AWS, GCP, Docker, Kubernetes, CI/CD · Stripe, HubSpot, Salesforce · HIPAA, HL7, FHIR, SEC Reg CF, multi-tenant SaaS, MVP development, fractional CTO
Steps for completing your project
After purchasing the project, send requirements so Waseem can start the project.
Delivery time starts when Waseem receives requirements from you.
Waseem works on your project following the steps below.
Revisions may occur after the delivery date.
API Planning & Design
Define endpoints, data models, REST/GraphQL structure
Database Architecture
PostgreSQL/MongoDB schema, models, relationships