You will get Backend Development | Scalable APIs & Secure Systems
Top Rated
Project details
As an Experienced backend-focused developer, I will build a custom CRM system tailored to your business workflows, not a generic template.
I focus on delivering a scalable, secure, and production-ready CRM that helps you manage leads, automate sales, and improve team productivity.
👉 I handle the complete development cycle:
Discovery → System Architecture → Backend Development → API Integration → Testing → Deployment
👉 You will get a powerful CRM system with:
✔ Lead Management & Sales Pipeline
✔ Role-Based Access Control (Admin / Team / Managers)
✔ Custom Workflows & Automation
✔ Secure REST APIs & Database Design
✔ Performance-Optimized Backend
✔ Scalable Architecture (ready for growth)
I don’t just build software, I build systems that support long-term business growth and efficiency.
CRM Development, Custom CRM, Backend Developer, API Development, Node.js, SaaS, Lead Management, Sales Automation, PostgreSQL, System Architecture, Webhooks, RBAC, Scalable Backend
I focus on delivering a scalable, secure, and production-ready CRM that helps you manage leads, automate sales, and improve team productivity.
👉 I handle the complete development cycle:
Discovery → System Architecture → Backend Development → API Integration → Testing → Deployment
👉 You will get a powerful CRM system with:
✔ Lead Management & Sales Pipeline
✔ Role-Based Access Control (Admin / Team / Managers)
✔ Custom Workflows & Automation
✔ Secure REST APIs & Database Design
✔ Performance-Optimized Backend
✔ Scalable Architecture (ready for growth)
I don’t just build software, I build systems that support long-term business growth and efficiency.
CRM Development, Custom CRM, Backend Developer, API Development, Node.js, SaaS, Lead Management, Sales Automation, PostgreSQL, System Architecture, Webhooks, RBAC, Scalable Backend
Web Programming Project
API DevelopmentProgramming Languages
JavaScriptCoding Expertise
Localization, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$1,600
|
Standard
$2,800
|
Advanced
$3,900
|
|---|---|---|---|
| Delivery Time | 12 days | 20 days | 30 days |
Number of Revisions | 1 | 2 | 2 |
Source Code |
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NU
Nat U.
Jun 5, 2026
Xamarin developer to maintain and update existing app, payment integration work, conversion to MAUI
I had an excellent experience working with Karan.
He successfully upgraded our mobile application from Xamarin.Forms to .NET MAUI and handled both the mobile app and the associated .NET backend services. The project involved a number of technical challenges, but he consistently demonstrated strong problem-solving skills, attention to detail, and a deep understanding of the mobile and backend ecosystems.
Throughout the engagement, he was responsive, professional, and proactive in identifying issues before they became problems. The migration was completed smoothly, performance improved, and the application remained stable throughout the process. He also communicated clearly, provided thoughtful recommendations, and was easy to work with from start to finish.
If you're looking for a developer with strong expertise in .NET, MAUI, mobile development, and backend services, I would not hesitate to recommend him. I look forward to working with him again on future projects.
He successfully upgraded our mobile application from Xamarin.Forms to .NET MAUI and handled both the mobile app and the associated .NET backend services. The project involved a number of technical challenges, but he consistently demonstrated strong problem-solving skills, attention to detail, and a deep understanding of the mobile and backend ecosystems.
Throughout the engagement, he was responsive, professional, and proactive in identifying issues before they became problems. The migration was completed smoothly, performance improved, and the application remained stable throughout the process. He also communicated clearly, provided thoughtful recommendations, and was easy to work with from start to finish.
If you're looking for a developer with strong expertise in .NET, MAUI, mobile development, and backend services, I would not hesitate to recommend him. I look forward to working with him again on future projects.
JW
Jeremy W.
Apr 17, 2026
.NET MAUI Mobile Developer Needed for iOS/Android App
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Idan b.
Feb 22, 2026
SaaS Developer Needed for PayPal Integration and QA
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Prince R.
Feb 12, 2026
Full-stack dev to complete and optimize auditing app
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Nahar G.
Nov 18, 2025
Mobile app redesign
About Karan
Full Stack Developer | AI | React Developer | Node.js | SaaS | FinTech
100%
Job Success
Surat, India - 7:52 pm local time
Top Rated Plus, top 3% of talent on Upwork. Full Stack, SaaS and AI Development.
Over 90% of the products I build ship to production, and most are still live and in daily use today.
ABOUT ME
✅ 12+ years and 50+ delivered products as a Full Stack Developer in React and Node, across SaaS platforms, AI apps, MVPs, and web application delivery
✅ $4M+ in client revenue impact and 60,000+ active users across the products I have built
✅ 20,000+ active users on a SaaS platform, where my React Developer work lifted engagement by 22%
✅ 10,000+ users on a healthcare web application, where React Developer ownership cut admin workload by 40%
✅ 15,000+ daily AI prompts processed on an AI platform I built, cutting manual resolution time by 40%
✅ 2,400+ completed orders and 480+ registered customers on an ecommerce and CRM MVP
✅ 90% faster order processing and 80% lower manager workload through workflow automation
✅ Top Rated Plus with a 100% Job Success Score on every contract, backend architecture through to production UI
WHERE I DELIVER
As a Frontend React Developer, 20+ systems with UI development, dashboards, and responsive builds across SaaS platforms, booking platforms, and ecommerce websites.
As a React and Next.js Developer, 15+ launches with 30% faster iteration through design to code and component development.
As a Full Stack Developer React Node, 25+ end to end builds with backend APIs, data architecture, and secure scalable systems from early stage MVP to live SaaS platform.
As a Full Stack Developer React Node, AI powered product builds: chatbots, RAG assistants, and automation with OpenAI, Claude API, FastAPI, and vector databases.
As a Full Stack Developer, 12+ backend heavy products with 28% lower delivery risk on Node.js and Python.
As a Full Stack Developer React Node, 6 to 18 month engagements as a long term development partner: scale existing platforms, professionalize, review, improve, and launch.
INDUSTRY IMPACT
SaaS Platform, B2B, Two Sided Marketplace: 50,000+ active listings, 35% higher conversion, and $2M+ in monthly transaction volume as a Full Stack Developer React Node.
Healthcare, Clinic Management SaaS, Telehealth: 10,000+ active users, 500+ daily appointments processed, and 15% fewer patient no shows as a Frontend React Developer maintaining 99.9% uptime.
AI Powered: 5+ products deployed with custom AI agents, chatbots, and RAG systems on OpenAI, Claude API, and FastAPI, processing 15,000+ daily prompts and cutting manual resolution time by 40%.
Logistics, ERP, Internal Workflow: up to 12 hours saved per order cycle, 30% faster reporting, and 40% fewer data entry errors across 5+ regional hubs as a Full Stack Developer React Node.
Fintech, LegalTech, PropTech MVP: 40% higher retention over 6 months and role based access for 5,000+ users through Frontend React Developer work.
Clients typically work with me when they need:
- a Full Stack Developer who can own frontend and backend
- a SaaS Developer who understands long-term scalability constraints
- a Backend Developer experienced with real production systems
- mobile app developer and React developer experience as a software developer
- backend services built with Node.js or Python by an experienced Python developer
- web applications with complex workflows and business rules from a senior web developer
- API-driven architectures and third-party integrations
- SaaS platforms designed to support growth, analytics and SaaS marketing data needs
- MVPs that can realistically evolve into long-term SaaS products
HOW I BUILD
Frontend as a React Developer: React, Next.js, TypeScript, JavaScript, Tailwind CSS, Redux, HTML5, CSS3, responsive design, real time UI.
Full stack and backend as a Full Stack Developer React Node: Node.js, Python, ASP.NET, PostgreSQL, MySQL, MongoDB, Redis, REST API, WebSockets, Stripe, payment, auth, and third party API integrations.
AI as a Full Stack Developer: OpenAI, Claude API, FastAPI, RAG, vector databases, LangChain, AI agents, chatbots, and workflow automation.
Also across the stack: Vue, Supabase, Firebase, Docker, AWS, Vercel, CI/CD, software architecture, and end to end delivery from MVP to live platform.
Steps for completing your project
After purchasing the project, send requirements so Karan can start the project.
Delivery time starts when Karan receives requirements from you.
Karan works on your project following the steps below.
Revisions may occur after the delivery date.
Requirement Analysis
Understanding your goals, features, and technical needs
Architecture Planning
Designing scalable backend structure & database