Vitalii A.

Senior Full-Stack & Cross-Platform Engineer | AI/LLM, Web, Mobile, Desktop

Looking for an all-around Senior Software Engineer who can tackle any technical challenge - from high-level AI agents to low-level reverse engineering and cross-platform apps?

With 15+ years of software development experience, I help businesses design, build, and scale complex applications across all major platforms and stacks. Whether you need a full-stack web application, an autonomous AI-driven workflow, or a high-performance cross-platform system, I deliver clean, maintainable, and scalable code.

TECHNICAL CAPABILITIES

AI & LLM Integration (Agentic Systems)
1.1. Building custom AI agents, fact-checking systems, and intelligent ad-selection engines.
1.2. Frameworks & Tools: LangChain, LangGraph, Semantic Kernel, n8n (no-code/low-code).
1.3. Providers & Models: OpenAI API, Anthropic, DeepSeek, Ollama (local LLMs), Hugging Face, OpenCV.

Full-Stack Web Development
2.1. Backend: Python (FastAPI, Flask, Django), C# (ASP.NET Core, CoreAPI, Razor), PHP (Laravel, Drupal, WordPress), Node.js.
2.2. Frontend: React, Next.js, TypeScript/JavaScript, HTML5/CSS3.
2.3. Databases & ORMs: PostgreSQL, MySQL, MSSQL, MongoDB, CosmosDB, Neo4j, pgvector. Entity Framework, SQLAlchemy, Prisma/Next ORM, Django ORM.

Desktop Application Development (Windows, macOS, Linux)
3.1. Cross-platform and native GUI apps: Qt (C++), WPF, Avalonia UI, Windows Forms, MFC.
3.2. Low-level system programming, socket communication, automation tools, and local encryption.

Mobile Development
4.1. Cross-platform apps with React Native.
4.2. Native Android development (Java, C++ / NDK).
4.3. Networking utilities, proxy systems, and embedded WebViews.

Cloud, DevOps & Automation
5.1. Cloud Platforms: AWS (Lambdas, Docker containers), Azure, GCP, Vercel.
5.2. Web Scraping & Automation: Human emulation algorithms, anti-bot bypass, automated checkouts, Selenium.
5.3. Reverse Engineering & Low-Level: .NET, Java bytecode, x86/x64/ARM Assembly.

FEATURED PROJECTS & HIGHLIGHTS

AI Fact-Checking Chat Engine: Engineered an embeddable LLM-powered fact-checking system using LangGraph + FastAPI, integrating custom web scrapers and computer vision (OpenCV).

AI Ad Selection & Analytics: Built a real-time ad targeting system based on text/chat analysis using LangGraph, FastAPI, and cross-platform embedding SDKs.