Upwork home
Sign up
Project Catalog
DesignDesign
Video & AudioVideo & Audio
Development & ITDevelopment & IT
MarketingMarketing
Writing & TranslationWriting & Translation
MoreMore

You will get Full Stack Developer - AI Features (LLM + RAG) for Your Product React.js

Vadym C.Status: Offline
Vadym C. Vadym C.
4.9
Top Rated
Preview imagePreview imagePreview imagePreview image

Let a pro handle the details

Buy Web Application Programming services from Vadym, priced and ready to go.
Vadym C.Status: Offline
Vadym C. Vadym C.
4.9
Top Rated
Preview imagePreview imagePreview imagePreview image

Let a pro handle the details

Buy Web Application Programming services from Vadym, priced and ready to go.

Project details

As a Full Stack Developer, react developer and web developer I add practical AI features that work in production: assistants, summarization, smart search, classification, auto-tagging, content generation. 50+ projects, 15+ hours/week saved for clients through AI automation.

As a backend developer and saas developer: define one clear AI use-case, success criteria, ship MVP fast and iterate on real results. Working with existing codebase. RAG pipelines, vector databases, LLM integration, prompt engineering, tool calling, structured output.
I work with my team. Production AI pipelines - not demos. If AI doesn't add ROI, I keep it simple.

Stack: React, Next.js, Node.js, NestJS, TypeScript, OpenAI, LangChain, PostgreSQL.

Keywords: full stack developer AI, full stack developer LLM, full stack developer RAG, full stack developer OpenAI, full stack developer chatbot, full stack developer AI integration, react developer AI, backend developer AI, web developer AI, saas developer AI, full stack developer vector database, full stack developer prompt engineering, senior web developer, full stack developer React, full stack developer Node.js, full stack ai saas developer
Programming Languages
HTML & CSS, JavaScript, TypeScript
Coding Expertise
Cross Browser & Device Compatibility, Performance Optimization, Security

What's included $9,500

These options are included with the project scope.

$9,500
  • Delivery Time 45 days
  • Number of Revisions 0
    • Source Code

Frequently asked questions

4.9
23 reviews
96% Complete
(22)
4% Complete
(1)
1% Complete
(0)
1% Complete
(0)
1% Complete
(0)

JK

Jamie K.
5.00
Jun 15, 2026
Map maker work It's my second time working with Vadym. He is a very talented developer who comes up with solutions for any obstacles that may arise. He likes to keep a constant stream of communication, which is great so I know what is going.

I'll certainly be working with Vadym again soon.

MW

Mario W.
5.00
Jun 15, 2026
Senior Full Stack Developer - Node.js, React, API Integrations, AI Workflows, n8n/Node-RED Great developer, solid skills in both React and Node.js. Communicates well, delivers on time. Looking forward to continuing working together

AF

Aloysius F.
5.00
Jun 9, 2026
Friendly betting web app Vadym is an excellent developer and programmer. Will definitely use again!

MW

Mario W.
5.00
Mar 27, 2026
Senior Full Stack Developer | Node.js, React.js | SaaS MVP Development & Architecture Working with Vadym and the team was a positive experience. They supported our SaaS MVP across both architecture and development, communicated clearly, and stayed proactive throughout the project. The work was delivered reliably, and overall the collaboration was smooth and professional

MW

Mario W.
5.00
Mar 11, 2026
Integrations between KlickTipp and other tools Vadym and the team delivered high-quality work on time and were proactive throughout. Communication was clear and reliable. Great experience - we’re happy to continue working together.
Vadym C.Status: Offline

About Vadym

Vadym C.Status: Offline
Full Stack Developer | React Node.js | SaaS Developer | Next.js
100% Job Success
4.9  (23 reviews)
Vyshneve, Ukraine - 3:49 pm local time
⚡ Available now. Need a Full Stack Developer who actually ships? 11 years, 50+ projects, 100K+ users. Full Stack AI SaaS Developer | Node.js React. I build your product end-to-end and take real ownership.

🏆 WHAT YOU GET
✔️ As a full stack developer and node.js developer I have shipped 50+ products with Node.js, React, Next.js, NestJS and TypeScript - from early-stage MVP to scalable SaaS platform with proven track record.

✔️ As a full stack ai saas developer I build AI-powered products with OpenAI, LangChain, n8n and RAG - AI agents, automation, semantic search. Full stack saasdeveloper ai agents and react ai features. 15+ hours/week saved through practical automation.

✔️ As a react developer, next.js developer and saas developer I deliver 30+ SPAs and SSR apps with react nextjs, react typescript and react supabase stack. MVP in 4-6 weeks. Full stack developer mern and mern stack experience included.

🔥 CLIENT WINS
✔️ 100K+ users on AI website builder - as a full stack developer ai I built real-time AI content generation, sites created in under 90 seconds. React, Next.js, Node.js, Stripe, AWS.

✔️ 80K+ users on AI agents platform - as a full stack ai saas developer I shipped multi-channel AI agents with 10+ integrations, saving clients up to 4K per month per agent.

✔️ 60% faster consulting prep - as a saas developer I built enterprise SaaS with AI-powered process mapping, multi-tenant architecture, RBAC, SSO and 200+ workflows mapped.

✔️ 70% cut in manual data processing - as a node.js developer I built logistics control tower with 8 API integrations and real-time tracking across 4 providers.

✔️ 300 req/s during peak traffic, zero downtime - as a back end developer node.js I scaled e-commerce backend and reduced response time from 1.2s to 180ms on 184M+ records database.

✔️ 38% better campaign performance - as a full stack developer crm I automated lead routing, data sync and CRM workflows with n8n saving 15+ hours/week.

✔️ 7x faster workflows for clients. 70% continue long-term collaboration. Response under 2 hours. Clear communication, work independently, async remote-first workflows.

🚀 WHERE I DELIVER
📌 As a saas developer and full stack developer saas I build multi-tenant platforms with RLS, RBAC, role-based access control, SSO, Stripe Connect and payment gateways. Admin dashboards, operations portals and reporting tools. As a full stack developer fintech and full stack developer healthcare I deliver scalable architecture for ongoing and complex project needs that clients build and maintain long-term.

📌 As a full stack developer marketplace and full stack developer ecommerce I build vendor management, inventory, commissions, Stripe payments, lead management and CRM integrations. As a full stack developer crm and b2b saas booking system developer I connect systems end-to-end working with existing platform or building from scratch. Gambling platforms, trading systems and custom dashboards with proven track record.

📌 As a react developer, next.js developer and front end developer I build with React, Next.js, TypeScript, Tailwind CSS and Firebase. Real-time features with react supabase and next.js supabase, react pwa for performance, react ai capabilities. From figma to react to react developer firebase integrations - nextjs frontend, full stack developer nextjs and web app developer react solutions.

📌 As a node.js developer and backend developer I build with Node.js, NestJS, Express.js, PostgreSQL, MongoDB, Redis, Supabase, Firebase and AWS. REST APIs, webhooks, WebSockets. Full stack node.js react architecture, react node integrations and node microservices. Discussing architecture decisions on every project.

📌 As a react native developer, react native app developer and mobile app developer I build cross-platform iOS and Android apps from MVP to production.

📌 As a web developer, javascript developer, software developer and full stack app developer I work with existing codebase daily. Take ownership, work independently, build and maintain production-ready architecture. Get up to speed quickly. Experience with full stack developer laravel, full stack laravel and wordpress developer for backend integrations and CMS projects when needed.

🔧 React, Next.js, JavaScript, TypeScript, Tailwind CSS, Firebase | Node.js, NestJS, Express.js, REST APIs, WebSockets | PostgreSQL, MySQL, MongoDB, Redis, Supabase, Stripe | React Native | n8n, OpenAI, LangChain | Docker, AWS, Vercel

📊 RESULTS
✅ 100K+ users on a single platform

✅ 184M+ records, 300 req/s, zero downtime

✅ Response time: 1.2s to 180ms

✅ 15+ hours/week saved through automation

✅ MVPs in 4-6 weeks, 7x faster workflows

✅ 70% long-term clients, response under 2 hours
🚀 Looking for a full stack developer or full stack ai saas developer who takes real ownership?

📞 Share your context - I will come back with structure and next steps

Steps for completing your project

After purchasing the project, send requirements so Vadym can start the project.

Delivery time starts when Vadym receives requirements from you.

Vadym works on your project following the steps below.

Revisions may occur after the delivery date.

Goals & examples

You share what you want the AI feature to do, who it’s for, and a few example inputs/outputs (or screenshots/links).

Plan & scope

I confirm the scope, define the acceptance criteria, and propose the simplest implementation plan + timeline.

Review the work, release payment, and leave feedback to Vadym.