Ihor

IHOR Kytsak
SENIOR FULL-STACK ENGINEER

FRONTEND PROFILE

React Next.js TypeScript Senior Full-Stack Engineer with 5 years of commercial experience
JavaScript Redux / RTK delivering production-grade systems. Built and stabilized
React Query React Native media-processing pipelines, subscription-based products, bilingual
Tailwind CSS Material UI marketing platforms, and DeFi portals with wallet authentication. Strong
Styled Comp. focus on API reliability, observability, controlled rollout practices, and
keeping delivery velocity high without sacrificing stability.
HTML5 / CSS3 Storybook

BACKEND
WORK EXPERIENCE
Node.js NestJS
Express.js Full-Stack Engineer | 01/2024 - present
FeathersJS REST API Blockchain-powered Product Journey Platform
GraphQL WebSockets
– Owned end-to-end delivery for a blockchain-powered product journey
BullMQ PostgreSQL platform focused on product provenance, sustainability claims, and
MongoDB Redis transparent supply-chain visibility.
JWT / Auth Web3 / RPC – Built core admin workflows for company/product management,
subscription access, product scanning, approval flows, campaign
management, and token-based user rewards.
DEVOPS & CLOUD – Developed public product journey pages with multilingual support,
consumer-facing product details, and map-based visualization of origin,
production, and delivery stages.
AWS Docker Kubernetes
– Integrated Web3 flows for blockchain-backed product records, including
Terraform CI/CD Nginx
smart contract interactions, transaction creation, approval handling, and
Vercel reliable state synchronization.
– Built AI and automation features using OpenAI API, scheduled jobs, and
X/Twitter /Telegram integrations for chatbot responses, generated posts,
PRACTICES and community engagement.
– Established deployment workflows with Docker, GitHub Actions, and AWS
▸Domain-Driven Design services, supporting fast product iteration while keeping production
▸API Contract Design releases controlled and reliable.

▸Observability & MTTR
React Next.js TypeScript React Query MUI Radix UI Stitches NestJS
▸Job Orchestration PostgreSQL TypeORM REST API Cron Jobs Stripe OpenAI API Web3
ethers Smart Contracts Docker GitHub Actions AWS S3 CloudFront
▸Caching Patterns
Secrets Manager Amplify Lambda DynamoDB Lightsail API Gateway
▸Performance Budgets
▸Incident Postmortems

Backend Engineer | 11/2022 - 12/2023
Gentler Streak - FitnessTrackerwith Readiness Guidance

– Owned backend services for account lifecycle, sync, and long-term
activity history, optimised for mobile connectivity constraints.
LANGUAGES – Designed aggregation pipelines for timelines and readiness summaries,
maintaining data correctness across months/years of user history.
▸Ukrainian - Native – Built subscription/entitlement pathways with audit-friendly state
▸English - B2 Upper-Int. transitions and backwards-compatibility safety rails to prevent
revenue-impacting regressions.
– Introduced rate limiting and defensive validation on core endpoints -
EDUCATION prevented abuse patterns and protected stability during traffic spikes.
React Native Node.js NestJS TypeScript PostgreSQL AWS HealthKit
Bachelor of Software​
CI/CD
Engineering 2016 - 2020

Lviv Polytechnic National​
University
Full-Stack Engineer | 01/2022 - 09/2023
Spicenet Portal - Web3 Ecosystem Portal

– Architected portal with explicit domain boundaries (quests, progression,
CONTACTS
rewards, leaderboard), enabling rapid campaign iteration without
destabilising core flows.
Telegram
– Implemented wallet-based authentication and message-signing flows with
LinkedIn consistent session behaviour across wallet providers.

Email – Built anti-abuse and data-integrity guardrails: idempotent reward claims,
server-side verification, replay-protection - eliminated fraudulent claim
attempts entirely.
– Designed cache-aware read paths for high-churn views (leaderboards,
progress).
– Established observability hooks for key funnels (quest completion, wallet
connect, claim success), enabling data-driven prioritisation.
React TypeScript Node.js PostgreSQL WebSockets Docker Web3 RPC
CI/CD

Full-Stack Engineer | 06/2020 - 01/2022
Tella - Screen Recording & Editing SaaS

– Owned backend delivery for core media workflows (asset ingest,
processing, conversion, publish-readiness), ensuring correctness under
large payloads.
– Designed and standardized API contracts powering editor/publishing
surfaces, keeping client behavior predictable across fast product iteration.
– Hardened processing paths by tightening failure handling, retries, and asset
consistency guarantees
– Introduced baseline observability (structured logging, alerting) on the most
failure-prone media paths, cutting MTTR from ~2h to <30 min.
– Established rollout discipline (small batches, instrumentation-driven
validation) for pipeline-impacting changes - zero regressions over 8
releases.
Node.js TypeScript NestJS PostgreSQL GraphQL AWS Docker
Kubernetes Terraform CI/CD