Fedya

Pavlyshynets Fedir
Full-Stack Developer | 6+ Years Experience | React · Next.js · TypeScript · Node.js · NestJS · Prisma
Budapest, Hungary | [відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація»)

SUMMARY
Full-Stack Developer with 6+ years of experience building scalable, high-performance web applications across B2C, B2B, and Web3/blockchain
domains. Strong expertise in React.js, Next.js, and TypeScript on the frontend, combined with solid backend experience using Node.js, NestJS,
Express.js, Prisma ORM, and PostgreSQL/MongoDB. Proven track record delivering end-to-end products, from architecting microservice
systems with gRPC/RabbitMQ communication to integrating blockchain protocols, cross-chain bridges, and multi-wallet authentication flows.
Experienced in both small focused teams and large cross-functional ones, taking ownership of architecture decisions, code quality standards,
and cross-team coordination with designers, backend engineers, QA, and product managers.

TECHNICAL SKILLS
Backend: Node.js, NestJS, Express.js, REST API, GraphQL, WebSockets, gRPC, Protocol Buffers, microservices architecture, API Gateway
pattern, SSR
Frontend: React.js, Next.js, TypeScript, JavaScript ES6+, TailwindCSS, Apollo GraphQL, HTML5, CSS3, responsive design, cross-browser
compatibility
Messaging & Communication: RabbitMQ, gRPC/Protobuf inter-service communication
Database & ORM: PostgreSQL, MongoDB, Mongoose, Prisma ORM, Redis, caching optimization, query optimization
Web3/Blockchain: Ethers.js, Web3.js, Wagmi, viem, solana/web3.js, MetaMask, WalletConnect, Phantom, Solflare, Tron Link, Ledger
SDK, DeFi, dApp, smart contract integration
State Management: Redux, MobX, Context API
Tools & DevOps: AI Agents, Git, GitHub Actions, CI/CD pipelines, Jest, React Testing Library, Docker, AWS (S3, EC2, ECS, CloudFront, SQS,
SNS, SES), Lighthouse, SEO optimization, Optimizely, A/B testing, Agile, Scrum
PROFESSIONAL EXPERIENCE

Vareger Groupe | Software Engineer Sep 2024 - Apr 2026 | Remote
Project: TransaTron Aug 2025 - Apr 2026
· Sole full-stack developer on the project, independently owning end-to-end delivery across frontend, backend, infrastructure, and Web3
integrations
· Designed and implemented a modular monolith backend architecture with clearly separated modules, Auth, Notifications, and Staking,
each with independent domain boundaries
· Optimized database queries and introduced Redis caching strategies, resulting in a 25% reduction in database load and a 15% improvement
in data retrieval speeds
· Architected scalable frontend structure, established code quality standards, built reusable UI component library, reduced development time
by 40%
· Built MVP staking dashboard from scratch, users could deposit tokens into a shared liquidity pool, track earned rewards, and withdraw
funds
· Developed a standalone crypto wallet supporting USDT transfers on the TRON blockchain with automatic fee abstraction, no TRX required
from users
· Deployed and managed backend on AWS ECS as a containerized NestJS modular monolith, used S3 for transaction receipt storage
· Designed and built a Claude Code AI agents plugin (5 agents) for TRON blockchain development, each agent specialized in a specific domain,
with automatic query routing and inter-agent delegation
· Owned full CI/CD pipeline (GitHub Actions), environment separation, release flow, and production deployment safety
Tech stack: React.js, Next.js, TypeScript, Node.js, NestJS, PostgreSQL, Prisma ORM, TailwindCSS, Ledger SDK, Tron Link, WalletConnect, AWS S3, ECS,
CloudFront, CI/CD
Project: Gunzilla Games, "Off The Grid" Sep 2024 - Aug 2025
· Contributed to the Web3 ecosystem for AAA game "Off The Grid", 14M+ registered users, 10K+ daily active players
· Contributed to the migration of legacy services to a modern NestJS framework, enhancing maintainability and developer productivity by
35%
· Built and maintained NestJS backend services with Prisma ORM for structured data management across game platform APIs
· On the marketplace backend, implemented Redis-based caching layer for high-frequency game items listing and pricing data, reducing DB
load on peak traffic, optimized PostgreSQL queries for item filtering
· Improved security score from 50 to 115 (Mozilla Observatory) via CSP policies, HTTPS headers, and server-side security middleware, a
+130% improvement

· Mentored a team of junior developers, conducting code reviews and implementing best practices that reduced post-deployment bugs by
30%
· Worked across 4 live platforms, blockchain explorer for custom L1 chain (8M+ transactions), cross-chain bridge (Solana to Ethereum), in-
game item marketplace, and Hacker Platform
· Integrated wallet connections for web and mobile, MetaMask, WalletConnect, Phantom, Solflare
· Participated in native token launch on Binance, collaborating with blockchain and backend teams on frontend integration
Tech stack: React.js, Next.js, NestJS, Node.js, TypeScript, Prisma ORM, Redis, Wagmi, viem, solana/web3.js, Ethers.js
Cleveroad | Software Engineer Feb 2023 - Aug 2024 | Remote
· Worked full-stack with a backend focus on On Location, WWE's official fan hospitality and VIP ticketing platform, owning the microservice
architecture, API Gateway + Auth microservice, Notifications microservice, Payment microservice, and Booking/Seats microservice,
synchronous calls via gRPC/Protobuf, async event-driven messaging via AWS SQS/SNS
· Modelled relational data (events, bookings, users) with Prisma schema on PostgreSQL, built the NestJS services behind it, enabled type-safe
queries and simplified migrations
· Managed media assets (event images, ticket PDFs) via AWS S3 with CloudFront CDN, backend deployed on AWS ECS
· Contributed to CI/CD pipelines with GitHub Actions, maintained high unit test coverage with Jest
· Built server-side filtering, search, and booking flows on the Next.js and Apollo GraphQL frontend, and set up A/B testing via Optimizely,
resulting in a +10% conversion rate
· Performed Lighthouse-driven performance optimization, bundle chunking, lazy loading, image optimization, improved Page Speed and INP
metrics by 35%
Tech stack: NestJS, Node.js, TypeScript, gRPC, Protobuf, AWS, Prisma ORM, PostgreSQL, Next.js, Apollo GraphQL, Contentful CMS
ThinkMobiles | Software Engineer Jan 2022 - Feb 2023 | Remote
· Worked full-stack with a backend focus, building and maintaining RESTful APIs on Node.js and Express for authentication, course
management, and content delivery, serving 10,000+ active users
· Designed custom middleware for logging, error handling, and input validation, improving API reliability and maintainability
· Wrote automated test suites with Jest and Mocha, raising code coverage to 80% and cutting production bugs by 20%
· Integrated Contentful CMS, cutting content update time by 50%, and implemented SEO improvements
· Deployed and supported the application on AWS EC2, gaining hands-on experience with cloud infrastructure and CI/CD workflows
· Built the React frontend, cut page load time by 40% through Redis caching, memoization, lazy loading, and bundle optimization, and
offloaded third-party scripts to web workers with PartyTown to reduce main thread blocking
Tech stack: Node.js, Express.js, MongoDB, TypeScript, React.js, Redux, Canvas API, Jest, React Testing Library, SEO
Freelance | Full-Stack Developer Mar 2020 - Dec 2021 | Remote, Ukraine
· Independently built and delivered full-stack web applications for international clients, managing development and client communication
end-to-end
· Integrated third-party APIs, implemented caching, developed React UI components, adopted TypeScript, GraphQL, and Material UI across
projects
· Wrote comprehensive unit and integration tests using Jest and Supertest, increasing code coverage to over 85%
· Designed and managed MongoDB database schema for storing user profiles
· Got initial commercial experience across frontend and backend, from requirements gathering to production delivery
Tech stack: React.js, Next.js, TypeScript, Node.js, Express.js, MongoDB, Mongoose

KEY ACHIEVEMENTS

· Scale: Built and maintained platforms serving 14M+ registered users with 100K+ daily active players
· Performance: Reduced page load time by 40% via Redis caching, improved Page Speed and INP metrics by 35%
· Security: Improved Mozilla Observatory score from 50 to 115 (+130%) via CSP headers and security hardening
· Business impact: +10% conversion rate via A/B testing, -50% deployment time with CI/CD automation
· Cost reduction: Cut blockchain transaction costs by 60% via TRON fee abstraction mechanism
· Web3: Processed 8M+ transactions on custom L1 blockchain, contributed to native token launch on Binance
· Architecture: Microservice systems with gRPC/Protobuf + RabbitMQ across 3+ projects, NestJS + Prisma patterns, reduced development
time by 40%
· Leadership: Mentored junior devs, led code reviews, established full-stack coding standards across teams
EDUCATION
Master's Degree in International Economics
Lviv Polytechnic National University | 2022 · 2024