10/15/2026 updated
100 % available
Senior Software Engineer & AI Developer
Gryfice, Poland
Worldwide
About me
Senior AI Full Stack Engineer building production SaaS, AI agents, automation platforms, and scalable web applications with Next.js, React, TypeScript, Python, FastAPI, Supabase, PostgreSQL, LangGraph, OpenAI, and AWS.
OpenAISupabaseJavaScriptAmazon Web ServicesComputer-Aided Software EngineeringSoftware as a ServiceData ArchitecturePython (Programming Language)LaravelPostgreSQLNext.jsTypeScriptWorkflowsBackendFastAPI
Senior AI Full Stack Engineer building production SaaS, AI agents, automation platforms, and scalable web applications with Next.js, React, TypeScript, Python, FastAPI, Supabase, PostgreSQL, LangGraph, OpenAI, and AWS.
? Senior Full Stack and SaaS Development
? Next.js, React, TypeScript and JavaScript
? Python, FastAPI and API Architecture
? OpenAI, Claude, LangGraph, RAG and AI Agents
? Supabase, PostgreSQL, pgvector and Redis
? Stripe, SaaS Billing and Subscription Systems
? AWS, Vercel, Docker and CI/CD
? Laravel and PHP for Existing Business Applications
I am a Poland based Senior AI Full Stack Engineer focused on building complete digital products from frontend experience to backend architecture, databases, AI workflows, automation, billing, and cloud deployment.
My background started with traditional full stack web development and business applications using JavaScript, React, PHP, Laravel, WordPress, Shopify, APIs, and relational databases.
Today, my main focus is modern AI powered SaaS development.
I help startups and businesses build AI products that are reliable outside the prototype stage, including authentication, permissions, data architecture, billing, background workflows, monitoring, AI model integration, and production deployment.
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I also have experience maintaining and extending established business systems using:
• Laravel
• PHP
• WordPress
• Shopify
• MySQL
• REST API integrations
• eCommerce workflows
This allows me to work with companies that need to modernize existing systems rather than rebuild everything from zero.
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• AI SaaS platforms
• AI agents and copilots
• RAG applications
• Workflow automation systems
• B2B SaaS products
• Internal business applications
• AI document processing
• Customer support automation
• API based platforms
• Subscription applications
• eCommerce integrations
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✅ Senior full stack ownership
✅ Production focused AI integration
✅ Clean and scalable architecture
✅ Strong API and database engineering
✅ SaaS authentication and billing experience
✅ Reliable cloud deployment
✅ Clear communication and long term support
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- Full time freelancer
- Available 40+ hours per week
- Poland and European timezone
- Available for EU, UK and US clients
-> Open to long term product development
Experience
Professional experience5 - 10 years
Freelancer since2021
Languages
EnglishFluent
Project history
Built AI enabled financial systems focused on credit risk, underwriting, fraud and automated decision workflows.
• Developed Python and FastAPI services
• Built Next.js financial interfaces
• Created LangGraph agent workflows
• Implemented RAG with PostgreSQL and pgvector
• Built document and cash flow analysis
• Developed underwriting support workflows
• Added structured AI outputs and validation
• Built human review and audit history
• Used Temporal for durable workflows
• Added AI and application observability
Niche Stack
LangGraph, Lending, Credit Risk, Fraud, FastAPI, pgvector, Temporal, Langfuse
Built and maintained full stack web applications across frontend, backend APIs, databases, integrations, and production infrastructure.
• Developed React and Next.js user interfaces
• Built Node.js and Python REST APIs
• Designed PostgreSQL schemas and migrations
• Integrated authentication and third party services
• Implemented Redis caching and background jobs
• Added automated testing and CI/CD workflows
• Supported AWS and Docker based deployments
• Investigated API failures and production performance issues
• Collaborated with product and design teams on feature delivery
Niche Stack
Next.js, React, Node.js, Python, PostgreSQL, Redis, Docker, AWS, REST APIs
Built Open Finance and embedded banking systems across APIs, financial data and payment workflows.
• Developed Python and Node.js backend services
• Built React and TypeScript interfaces
• Designed PostgreSQL financial data models
• Integrated bank data and payment APIs
• Developed PSD2 and consent workflows
• Built asynchronous processing with Redis
• Implemented authentication and access controls
• Added reconciliation and reporting services
• Built automated tests and CI pipelines
• Supported cloud deployments and production monitoring
Niche Stack
Python, React, PostgreSQL, PSD2, Open Banking, Payments, Redis, REST APIs
Certificates
Professional Cloud Developer
Cloud Credential Council2025
Agentic AI Builder
CertNexus2024
PCPP1 Certified Professional Python Programmer
OpenEDG Python Institute2024