You will get MVP App for your idea (iOS, Android, React, JavaScript)
Top Rated
Project details
Looking for web, mobile, or full-stack development for your business or startup? With more than 8 years of experience and more than 20 complex projects behind - ready to bring in Javascript expertise to build Web & Mobile apps that just get what the business wants
Key Features:
• Customized Functionality: Tailor your web app to perform precisely as your business demands, with features crafted to address your unique requirements.
• Scalability: Future-proof your digital presence with a scalable architecture, allowing your web app to grow seamlessly as your business evolves.
• Responsive Design: Guarantee an exceptional user experience across devices with a responsive design that adapts to various screen sizes, enhancing accessibility for your target audience.
• Security Measures: Prioritize data integrity and user privacy with robust security protocols, safeguarding your web app against potential threats.
• Collaborative Development: Experience a transparent and collaborative development process, with regular updates, feedback loops, and a commitment to meeting project milestones efficiently.
Key Features:
• Customized Functionality: Tailor your web app to perform precisely as your business demands, with features crafted to address your unique requirements.
• Scalability: Future-proof your digital presence with a scalable architecture, allowing your web app to grow seamlessly as your business evolves.
• Responsive Design: Guarantee an exceptional user experience across devices with a responsive design that adapts to various screen sizes, enhancing accessibility for your target audience.
• Security Measures: Prioritize data integrity and user privacy with robust security protocols, safeguarding your web app against potential threats.
• Collaborative Development: Experience a transparent and collaborative development process, with regular updates, feedback loops, and a commitment to meeting project milestones efficiently.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$30,000
|
Standard
$40,000
|
Advanced
$50,000
|
|---|---|---|---|
| Delivery Time | 40 days | 55 days | 70 days |
Number of Revisions | 3 | 5 | 7 |
Design Customization | - | ||
Content Upload | - | - | |
Responsive Design | |||
Source Code |
Frequently asked questions
31 reviews
(29)
(2)
(0)
(0)
(0)
This project doesn't have any reviews.
AD
Anna D.
Dec 19, 2025
30 minute consultation
It was a great and very professional react native developer. I received detailed, practical recommendations and all the necessary documentation. Oleg is a true professional who clearly understands the topic and explains everything in a structured and helpful way. Highly recommended.
TM
Tobias Hahn M.
Dec 15, 2025
Birdie App
Amazing cooperation! Quick onboarding, GREAT project management from their side and overall really nice work.
AD
Alina D.
Oct 15, 2025
30 minute consultation
One of the best experiences I’ve had on Upwork!
AD
Alina D.
Oct 3, 2025
30 minute consultation
Great and very useful consultation!
EB
Ethan B.
Jul 7, 2025
Mobile App Development (React Native) for Social Community App
Available, lot of skills, good english and efficient and fast work. I recommend
About Oleg
AI Agent Developer | PhD | AI Chatbot automation | Agentic AI RAG MCP
90%
Job Success
Cascais, Portugal - 9:48 am local time
ABOUT ME
"You built an interesting project in very short time."
Saket Agarwal (Director of Engineering at Salesforce), CTO at evluv
10+ years, $600K+ earned on Upwork, 10,472+ hours billed. Top Rated Plus.
What is running in production right now:
✅ Healify: AI health companion. Idea to production MVP in 6 months, ~$2M raised
✅ 300+ chats/day on a RAG support and lead-gen chatbot for a UK energy company
✅ 100K+ documents through RAG and OCR pipelines — invoices and bills of lading
for port logistics
✅ 6M+ users on RL Garage, cross-platform mobile app
✅ Production AI support agent on LangChain — intent classification, structured tool
calling, multi-turn regression evals in LangSmith, and a full compliance pass for a
regulated subscription business
✅ Self-hosted RAG over engineering drawings — SVG/DXF parsing, vector retrieval,
knowledge-graph layer for auditable answers with citations
✅ AI voice agent — inbound and outbound calls, lead qualification, appointment
booking, CRM-connected
✅ 10,000+ active users on a multi-tenant AI SaaS platform — Stripe billing, RBAC,
row-level security
✅ 25+ AI automation workflows (LanChain, Agents SDK) wiring AI agents into CRMs, Slack,
Telegram and WhatsApp
💬 3 of my last 3 paid consultations turned into ongoing projects
WHERE I DELIVER
AI Agent Developer — custom AI agents and agentic systems with LangChain, LangGraph
and MCP: tool calling, multi agent workflows, error handling, observability, evals,
production deployment.
AI SaaS Developer — multi tenant AI SaaS platforms and SaaS MVPs on Next.js, Node.js,
Python FastAPI, Supabase and Stripe billing. Idea to production in 6-12 weeks.
AI Chatbot Developer — RAG chatbots and AI assistants for customer support and lead
generation: WhatsApp, Telegram, web widgets, CRM integrations, human handoff.
MCP Developer — custom MCP servers connecting your APIs, databases and internal tools
to Claude Desktop, ChatGPT and Cursor.
RAG Developer / LLM Developer — retrieval pipelines with pgvector and Pinecone:
embeddings, hybrid search, reranking, grounded answers with citations.
Generative AI Developer / Python AI Developer — OpenAI API and Anthropic Claude API
integrations inside existing products, without breaking what already works.
INDUSTRY IMPACT
AI SaaS Platform, AI Chatbot SaaS, RAG Knowledge Base — 10,000+ users, subscription
and usage-based billing, 99.9% uptime.
Document Automation, Document Intelligence, OCR AI — 2K+ documents processed,
90%+ manual work reduction in port logistics.
Ecommerce Chatbot, WhatsApp Automation, Customer Support AI — 300+ chats/day with
lead capture and human handoff.
Healthcare AI, Real Estate AI, Fintech MVP, EdTech AI — AI agents, RAG systems and
AI SaaS delivered across regulated and non-regulated domains.
Voice-to-Book AI App, Cross-Platform Mobile AI — 5.0 stars on App Store and
Google Play, shipped solo as an AI application developer.
HOW I BUILD
25+ agent builds: langchain, langgraph, mcp server, tool calling, function calling,
multi agent systems, agentic workflows, prompt engineering, rag pipeline,
retrieval augmented generation, langsmith evals.
15+ platforms: nextjs, react, typescript, nodejs, python fastapi, supabase, postgres,
pgvector, pinecone, stripe, aws, azure, vercel.
10+ bots: whatsapp chatbot, telegram bot, conversational ai, knowledge base chatbot,
customer support ai, openai api, anthropic claude api, gpt-5.
One full stack AI developer, no hand-offs: agent logic, RAG layer, backend,
frontend, deployment, and the evals that prove it still works next month.
🤝 HOW WE START
Book a $50 consultation (my last 3 all turned into ongoing projects) or start with the
AI Product Audit in my catalog. Tell me what you are building and I will be honest
about the fastest way to ship it — including when you do not need an AI agent at all.
Need an AI agent developer or AI SaaS developer who actually ships?
Message me.
Steps for completing your project
After purchasing the project, send requirements so Oleg can start the project.
Delivery time starts when Oleg receives requirements from you.
Oleg works on your project following the steps below.
Revisions may occur after the delivery date.
Project Initiation
What will be done: - Defining the project scope, goals, and objectives - Establishing communication channels - Conducting initial feasibility studies and risk assessments - Developing a high-level project plan
Planning
It includes - Creating a detailed project plan, including timelines and milestones - Defining tasks, responsibilities, and resource requirements - Establishing a system for tracking progress and managing changes