You will get AI Developer for Agentic AI Web Apps in Python and FastAPI
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Project details
AI agents that do work, not chatbots that answer questions.
I build systems that take a goal and act on it: pull data from your tools, decide the next step, call APIs, write results back, and escalate to a human when they should. Research assistants, support automation, document processing, lead qualification, internal copilots over your own data.
The hard part isn't calling a model — it's making it reliable. I handle retries, guardrails, cost control, logging of every decision, and evaluation so you can prove it works before it touches customers.
AI Developer for agentic AI web apps in Python and FastAPI — this is my specialisation. I build the backend in Python with FastAPI, add RAG pipelines over your documents, and integrate OpenAI, Claude or open models running on your own infrastructure. The interface is React or Next.js, with Node.js or Firebase where the stack calls for it. You get a working system with documentation, not a notebook demo.
Fixed scope, fixed price, and an honest answer if AI isn't the right tool for your problem.
I build systems that take a goal and act on it: pull data from your tools, decide the next step, call APIs, write results back, and escalate to a human when they should. Research assistants, support automation, document processing, lead qualification, internal copilots over your own data.
The hard part isn't calling a model — it's making it reliable. I handle retries, guardrails, cost control, logging of every decision, and evaluation so you can prove it works before it touches customers.
AI Developer for agentic AI web apps in Python and FastAPI — this is my specialisation. I build the backend in Python with FastAPI, add RAG pipelines over your documents, and integrate OpenAI, Claude or open models running on your own infrastructure. The interface is React or Next.js, with Node.js or Firebase where the stack calls for it. You get a working system with documentation, not a notebook demo.
Fixed scope, fixed price, and an honest answer if AI isn't the right tool for your problem.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Localization, Security, DesignWhat's included
| Service Tiers |
Starter
$399
|
Standard
$1,299
|
Advanced
$1,999
|
|---|---|---|---|
| Delivery Time | 9 days | 18 days | 30 days |
Number of Revisions | 1 | 3 | 5 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - | - | - |
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OG
Oleksii G.
Jul 20, 2026
Senior React Developer (Node.js, Next.js, Python, AI) - Early-Stage AI Project
Great communication, and we’ve already wrapped up the first small milestone. Thanks, Alex and the Olearis team!
SU
Simon U.
Jun 4, 2026
Code the language learning app LinguaLeap/Disign exists already
Honestly one of the best dev experiences we’ve had on Upwork. Olearis team built our Flutter language learning app and absolutely nailed it. The project wasn’t easy (custom learning logic, gamified flows, tons of interactive screens) and they handled all of it like pros. The team understood what we wanted, followed the designs closely, and was always easy to talk to. They were responsive and really cared about making the product work well. I’d gladly work with them more.
OL
Olena L.
Apr 14, 2026
React Engineer for Platform Audit & Future Collaboration
It was a great experience working with this React Developer and the whole team at Olearis. Communication was smooth and clear, and everything was handled quickly and professionally. They delivered fast and with high quality. Looking forward to working together again in the future.
JW
James W.
Mar 24, 2026
Need : team of passionate, highly experienced web developers (SEO, usability, AI photo editor)
Great job!Thank you for amazing work by olearis team. Great communication and execution! Best of luck :)
JB
Josh B.
Mar 14, 2026
Teamword Game
Olearis was a fantastic partner throughout my work with them. Very responsive, creative, fast and easy to work with. I'd highly recommend them!
About Alexander
Full Stack Developer | AI Developer | React Developer
100%
Job Success
Kyiv, Ukraine - 7:14 am local time
⚛️ React Developer • Full Stack Developer • AI Developer
🔥 𝗖𝗹𝗲𝗮𝗻 𝗮𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲, 𝗳𝗲𝘄𝗲𝗿 𝗿𝗲𝗯𝘂𝗶𝗹𝗱𝘀, 𝗳𝗮𝘀𝘁𝗲𝗿 𝗹𝗮𝘂𝗻𝗰𝗵
I'm Alex. I run product delivery at Olearis with a 30-person team, and I help founders and startups ship web, mobile, and AI products that launch on time, scale cleanly, and don't need rebuilding later. As a full stack developer and React developer, I take ownership from idea to production, so you get one accountable partner instead of five contractors and don't pay to fix the same things twice.
📊 𝗥𝗲𝘀𝘂𝗹𝘁𝘀 𝗳𝗿𝗼𝗺 𝘁𝗵𝗮𝘁 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵
12M+ users, that's what we shipped in social mobile products.
1M+ users and a 4.8 App Store rating, that's our AI mental health work.
80+ companies including Bank of America and Citibank trust software we built.
36+ education apps run on AI tutor logic we designed.
🧩 𝗪𝗵𝗮𝘁 𝗜 𝘄𝗼𝗿𝗸 𝗮𝗰𝗿𝗼𝘀𝘀
I lead builds end to end as a full stack developer, web developer, React developer, react native developer, mobile app developer, Python developer, AI Developer, and WordPress developer. 16+ years in production. The rule is simple: build it properly from the start, so your next developer doesn't have to rewrite it later.
🔥 𝗪𝗵𝗮𝘁 𝗜 𝗵𝗲𝗹𝗽 𝘄𝗶𝘁𝗵
⚛️ Frontend & web. As a React developer and web developer, my team and I build SaaS platforms, dashboards, admin panels, marketplaces, and web apps with modern React patterns, clean architecture, Figma-to-code accuracy, and accessibility (WCAG 2.1 AA). React web development done right goes past screens: performance, reusable components, and maintainability.
🧱 Full stack. As the full stack developer owning the architecture, I connect frontend, scalable backend, mobile, Firebase, FastAPI, role-based access (RBAC), OAuth flows, and AI logic into one production-ready system. Whether it's a full stack developer react node build, a python full stack developer setup, or full stack developer php and full stack developer laravel work, you get one owner instead of five.
🤖 AI. On the AI Developer side, we build AI that's useful inside the product: assistants, agentic workflows, AI agent development, LLM integration, recommendations, and AI dashboards. From ai chatbot developer work to ai software developer system design, an AI Developer only earns their place when machine learning features are useful, not just clever in a demo. A data scientist explores the data, a Python developer turns it into services, and an AI Developer ships it, plus power bi developer reporting dashboards.
🐍 Backend & Python. As a Python developer with deep FastAPI experience, I build APIs, integrations, automation, data pipelines, machine learning workflows, and backends that handle real users. If your backend feels fragile, I step in as a Python developer and full stack developer to clean it up: readable, tested, production-ready, easy for the next data scientist or web developer to support.
📱Mobile. As a react native developer and mobile app developer, I build iOS and Android apps that connect cleanly to backends, APIs, subscriptions, payments, and push. A strong react native mobile app developer thinks about performance, release flow, and future support. Need cross-platform? A flutter developer can support Flutter or help you choose the right stack.
🌐 WordPress. As a WordPress developer, I handle marketing sites, landing pages, and CMS builds beside the main product, so your React developer, full stack developer, and WordPress developer work stays one consistent product story.
𝗣𝗿𝗼𝗱𝘂𝗰𝘁 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲
🟣 Parlor, social platform, 12M+ users
🟢 UpLife, AI mental health app, 1M+ users, 4.8★
🔵 Notate, secure productivity, trusted by Bank of America & Citibank
🟠 Fillrr, AI document app with smart parsing
🔴 Beatly, SaaS connected to Netflix, Uber, Spotify & 250M+ creators
🟤 HearMeOut, AI 24/7 therapy companion
⚪ Exam Prep Apps, 36+ education apps with AI tutor logic
💰 𝗪𝗵𝘆 𝘁𝗵𝗶𝘀 𝘀𝗮𝘃𝗲𝘀 𝘆𝗼𝘂𝗿 𝗯𝘂𝗱𝗴𝗲𝘁
✅ Clean React developer and web developer work means fewer frontend bugs.
✅ Thoughtful full stack developer work means frontend, backend, and mobile aren't fighting each other.
✅ Reliable Python developer and FastAPI work means a backend easy to scale and monitor.
✅ Good react native developer, flutter developer, and mobile app developer work means fewer mobile fixes after release.
✅ Practical AI Developer, machine learning, and data scientist work means AI features that are useful, not trendy.
📩 Need a React developer, web developer, full stack developer, or AI Developer? Text me and I'll tell you honestly what it'll take.
🔑 Areas: React Developer • Full Stack Developer • AI Developer • web developer • wordpress developer • mobile app developer • react native developer • python developer • machine learning
Steps for completing your project
After purchasing the project, send requirements so Alexander can start the project.
Delivery time starts when Alexander receives requirements from you.
Alexander works on your project following the steps below.
Revisions may occur after the delivery date.
Feasibility review
We define the task and I tell you straight whether an AI agent solves it, or whether simpler automation does the job cheaper.