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YAROSLAV
KHMARSKYI
FULL-STACK WEB DEVELOPER
Email: [открыть контакты](см. выше в блоке «контактная информация»)
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WHY ME WORK HISTORY
Full-Stack Web Developer focused on React/Nest.js, AWS,
and AI-integrated products, with 4 years of experience Full Stack Developer
shipping end-to-end features across frontend, backend, Feb. 2025 – Jul. 2026
and infrastructure. Strongest work spans web3, crypto, and
ANTIFRAUD SYSTEM
AI platforms with ownership of product-facing systems.
Built an automated bot detection system for casino and betting sites,
HIGHLIGHTED SKILLS replacing a manual review process with real-time classification of
suspicious sessions and accounts
Languages - Javascript, Typescript, Python
Implemented behavioral analysis (mouse movement, click patterns,
session timing) and device fingerprinting to distinguish bots from real
Back-end - Node.js, Nest.js, Express.js
users
Designed and built an API and web interface for reviewing flagged
Front-end - React.js, Next.js, Vue.js, HTML5/CSS3
activity, with search and filtering across multiple parameters plus
metrics and sorting
State Management - Redux Toolkit, Zustand, RxJS Owned the architecture and technology decisions across the stack

Data Visualization - PixiJS, Chart.js, D3.js INFRASTRUCTURE ORCHESTRATION WITH NOMAD
Introduced HashiCorp Nomad to orchestrate services across 8 servers,
AWS - S3, EC2, AMI, Cloud Watch, Load Balancer,
replacing manual service management
CloudFront, Auto Scaling Groups Set up and configured the Nomad cluster to automate deployment and
scheduling of services
Databases - MySQL, PostgreSQL, MongoDB Improved operational efficiency and reliability as the infrastructure
grew
ORM: TypeORM, Prisma, Drizzle
CRYPTO CASINO SERVICES
API & Integration - REST API, WebSocket, GraphQL, RPC
Migrated two production casino sites from a legacy frontend
architecture to a modern one, with a new design, faster load times,
Other - GIT, Bitbucket, Jira, Asana
and smaller bundle sizes
Contributed to technical decisions as part of a 10-person team,
Basic knowledge - PHP, Solidity, FunC, Rust
proposing and discussing architecture and implementation
approaches
AI Integration - LLM integration, prompt engineering, and
Made backend adjustments as needed to support frontend changes
intelligent workflow development
and new requirements
Onboarded two new developers and took part in code reviews to help
maintain quality across the team
PREVIOUS EDUCATION
Full Stack Developer
National University "Zaporizhzhia Polytechnic" J u l . 2 0 2 4 – F e b . 2 0 2 5
MASTER OF ENGINEERING | 2015 - 2020 CRYPTO TG GAME
Electric drive and automation of industrial plants Contributed to a Telegram-based tower defense game built with
PixiJS with crypto rewards for players, owning the payment system,
animations, and bug fixes
LANGUAGES Built the payment system handling in-game crypto transactions
English - Intermediate Implemented new animations and sound effects and improved existing
Ukrainian - Fluent ones to enhance gameplay
Russian - Fluent Fixed bugs across game logic and mechanics to improve stability
WORK HISTORY
Full Stack Developer
Jan. 2022 – Jul. 2024
AI-POWERED CONTENT GENERATION PLATFORM
Worked in a team on an AI platform that turns a user's text prompt into a customizable website — and later books — as the product scaled
Implemented block-level customization, letting users edit any section manually or by re-prompting AI to regenerate it
Integrated ChatGPT for text generation and Midjourney/DALL-E for images
Built an admin panel with analytics (visit and view statistics) and subscription management
Automated deployment on AWS using GitHub Actions for seamless releases and updates

AI-POWERED GREETING CARD GENERATOR
Built a full-stack AI greeting card generator solo — React frontend, Nest.js backend
Integrated OpenAI for text and Midjourney/DALL-E for image generation
Implemented user management and payment processing

AI PERSONA CHAT WIDGET
Built an embeddable iframe chat widget (frontend + backend) that clients drop into their site, letting visitors ask questions and get answers in
the client's own voice
Integrated an LLM trained on the client's talks to reproduce their speaking style
Configured TLS certificates with Let's Encrypt / Certbot

NFT MARKETPLACE & WEB3 GAME PLATFORM
Built an NFT marketplace from scratch on Ethereum, letting the client sell NFTs directly and avoid third-party platform fees (e.g. OpenSea)
Implemented wallet integration (MetaMask) and interaction with Ethereum smart contracts using Ethers.js, handling transactions and user
balances
Developed the marketplace's full UI from the provided design, owning the entire frontend
Contributed to the companion browser-based Godot game: built the in-game currency bundle purchase flow and HTML-side animations (e.g.
loading screen) driven by Godot's output