09/25/2026 updated
100 % available
AI Full-Stack Developer | LLM Apps, RAG & Agents | Next.js, Python, Claude
Krakow, Poland
Only remote
Master of ScienceAbout me
I build production-ready AI apps, RAG systems, and agents with Next.js, Python, and Claude. I help teams turn AI prototypes into scalable products with reliable workflows, clean integrations, and real business value.
AI AgentsTailwind CSSOpenAILangChainSupabaseJavaScriptPHPAmazon Web ServicesDevOpsDjangoPython (Programming Language)PostgreSQLNode.jsNext.jsTypeScript
AI Application Development & LLM Integration
Expertise in building production-grade LLM-powered applications including RAG pipelines, multi-agent workflows, and document intelligence systems using Claude, OpenAI/Anthropic APIs, LangChain, and LangGraph.
Full-Stack Development with React & Node.js
Strong command of full-stack development using React, Next.js, Node.js (NestJS), and TypeScript for building scalable SaaS platforms, multi-tenant dashboards, and AI-native web applications.
Python & Backend Engineering
Proficiency in Python and FastAPI for building backend services, data pipelines, and AI-powered features including automated tagging, document summarization, and model serving.
SaaS Platform Architecture
Design and implementation of multi-tenant SaaS platforms with Row-Level Security, authentication, billing via Stripe, and Edge Functions using Supabase and PostgreSQL.
Cloud & DevOps (AWS, Docker, CI/CD)
Hands-on experience with AWS, Docker, CI/CD pipelines, and DevOps practices for deploying and maintaining scalable, production-ready cloud applications.
Database Engineering (PostgreSQL, MongoDB, Supabase)
Implementation of PostgreSQL data models, query optimization, caching layers, pgvector for RAG pipelines, and MongoDB for various application backends.
Automation & Workflow Orchestration
Setup of n8n and cron-based automation to orchestrate multi-step agent workflows and webhook integrations, enabling complex business logic automation for clients worldwide.
REST API Development & Third-Party Integrations
Design and integration of REST APIs and third-party services including payments, shipping, analytics, and AI APIs for international clients across multiple industries.
React Native & Mobile Development
Experience with React Native for cross-platform mobile application development as part of a broad full-stack skill set.
Expertise in building production-grade LLM-powered applications including RAG pipelines, multi-agent workflows, and document intelligence systems using Claude, OpenAI/Anthropic APIs, LangChain, and LangGraph.
Full-Stack Development with React & Node.js
Strong command of full-stack development using React, Next.js, Node.js (NestJS), and TypeScript for building scalable SaaS platforms, multi-tenant dashboards, and AI-native web applications.
Python & Backend Engineering
Proficiency in Python and FastAPI for building backend services, data pipelines, and AI-powered features including automated tagging, document summarization, and model serving.
SaaS Platform Architecture
Design and implementation of multi-tenant SaaS platforms with Row-Level Security, authentication, billing via Stripe, and Edge Functions using Supabase and PostgreSQL.
Cloud & DevOps (AWS, Docker, CI/CD)
Hands-on experience with AWS, Docker, CI/CD pipelines, and DevOps practices for deploying and maintaining scalable, production-ready cloud applications.
Database Engineering (PostgreSQL, MongoDB, Supabase)
Implementation of PostgreSQL data models, query optimization, caching layers, pgvector for RAG pipelines, and MongoDB for various application backends.
Automation & Workflow Orchestration
Setup of n8n and cron-based automation to orchestrate multi-step agent workflows and webhook integrations, enabling complex business logic automation for clients worldwide.
REST API Development & Third-Party Integrations
Design and integration of REST APIs and third-party services including payments, shipping, analytics, and AI APIs for international clients across multiple industries.
React Native & Mobile Development
Experience with React Native for cross-platform mobile application development as part of a broad full-stack skill set.
Experience
Professional experience5 - 10 years
Freelancer since2018
Languages
EnglishNative speakerPolishNative speaker
Project history
Led development of AI-augmented SaaS features and agent workflows for fintech, healthcare and logistics companies across 14 countries using React, Node.js, Python, LangChain/LangGraph, and OpenAI/Anthropic APIs. Designed RAG pipelines with pgvector and Supabase Postgres, built tool-calling agents, React + Supabase SaaS frontends with Row-Level Security and Stripe billing, set up n8n and cron-based automation, and owned architecture decisions and code review standards.
Developed multi-tenant SaaS platforms, internal dashboards, and AI-powered web apps for US- and European-based startups and SMEs. Built React/Next.js frontends and Node.js (NestJS) backends with TypeScript, architected event-driven microservices and API integrations, introduced LLM-powered features using Python services, and mentored junior developers.
Built and maintained full-stack SaaS web applications for global clients including HRM, LMS and e-commerce platforms using React and Node.js + PostgreSQL. Designed REST APIs, integrated third-party services, implemented PostgreSQL data models with query optimization, and contributed to early AI-assisted features such as smart categorization and helpdesk automation.
Certificates
AWS Certified Developer – Associate
Amazon Web Services (AWS)2025
AI Agent Builder Associate
Microsoft2025
Azure AI Apps and Agents Developer Associate
Microsoft2024