Contact information

You can get this candidate's contact information from https://www.work.ua/resumes/4837499/

Work experience

AI Engineering Instructor

from 04.2026 to now (7 months)
AI courses for engineers, Дистанційно (IT)

AI courses for engineers.
Topics: Claude Code, multi-agent workflows, LLM APIs, prompt engineering, automation.

- Design and teach practical courses on AI-assisted software engineering: agentic coding with Claude Code / Cursor / Codex, lead & sub-agent orchestration, repo context (CLAUDE.md / AGENTS.md) and guardrails.
- Cover integrating LLMs into production products — tool use, streaming, cost & quota control, evaluation and safe automation of review, testing and release workflows.

Full Stack Developer

from 01.2026 to now (10 months)
trvl.best, Дистанційно (IT)

Founder & Owner · Full-Stack Engineer (Frontend, Backend, QA).
AI travel planner with freemium credits & Pro subscriptions.
Stack: React, TypeScript, Vite, Cloudflare Pages Functions, D1 (SQL), KV, Anthropic Claude API, Firebase Auth, Vitest, Playwright.

- Own the product end to end: product vision, architecture, frontend, backend, database, testing, CI/CD, security, release and growth analytics.
- Designed and built the payments platform with 4 providers — card payments via lava.top hosted invoices, Stripe, crypto via NOWPayments and RevenueCat for mobile — covering monthly / quarterly / annual plans, single purchases, promo & referral codes.
- Secured payment webhooks with HMAC signature verification (SHA-256 / SHA-512) and made processing idempotent via unique provider charge IDs and event de-duplication.
- Built an append-only payments ledger with per-charge records and multi-currency → USD normalisation for revenue, cohort and ROAS reporting.
- Locked plan and expected amount server-side at invoice creation to guarantee pricing integrity.
- Implemented refunds & chargebacks: server-side eligibility engine, one-refund-per-account via partial unique DB index, rate-limited API, admin back-office, Telegram alerts, referral-bonus clawback.
- Built a usage-based credit ledger (reserve → settle → refund) and AI quota / rate limiting.
- Backend on Cloudflare Workers with D1 SQL — 50+ versioned migrations, KV caching, cron jobs, Google OAuth + email auth, CSP and security headers.
- Quality: 370+ test files (Vitest, RTL), Playwright E2E on desktop and phone; GitHub Actions CI with secret scanning.
- Production LLM features on the Anthropic Claude API (itinerary generation, streaming chat); AI-native multi-agent workflow (Claude Code, Codex) — 800+ commits shipped.

Front-End Developer

from 06.2025 to 08.2026 (1 year 3 months)
EPAM Systems, Дистанційно (IT)

EPAM Systems (Georgia, Batumi) · Radio Streaming Service — live radio & on-demand audio streaming platform.
Stack: React, Next.js, TypeScript, WebSocket, Jest, Playwright.

- Developed the web client of a radio streaming service — live stations, on-demand shows and podcasts — with React, Next.js and TypeScript.
- Built a persistent cross-page audio player (HLS streams, Web Audio API, Media Session API) with uninterrupted playback across navigation and graceful recovery from network drops.
- Implemented real-time "now playing" metadata and live updates over WebSocket; tuned rendering for high-traffic station pages (SSR, code-splitting, lazy loading, Core Web Vitals, SEO).
- Delivered premium subscription / paywall UI and entitlement checks integrated with backend billing APIs.
- Ensured accessibility (WCAG 2.1 AA) and i18n; covered features with unit, integration and E2E tests (Jest, React Testing Library, Playwright) in CI/CD.
- Worked in a distributed Agile team with backend, QA and design; introduced AI-assisted development and automation (Claude Code, Copilot) for test generation and code review.

Front-End Team Lead

from 07.2023 to 05.2025 (1 year 11 months)
Scilife, Дистанційно (IT)

Front-End Engineer · Team Lead. Compliance & Quality Management SaaS (regulated industries), remote.
Stack: React, Next.js, TypeScript, React Native.

- Led a cross-functional frontend team of 8 engineers building a React / Next.js SSR platform and a paired React Native mobile app for regulated customers (audit trails, e-signatures, access control).
- Migrated legacy pages to Next.js App Router with React Server Components, reducing TTFB by 35% and bundle size by 22%.
- Architected a shared Storybook design system across web and mobile, cutting UI inconsistencies by ~40%.
- Integrated Datadog RUM observability (−40% time to detect UI regressions); introduced SonarQube quality gates (−30% production defects).
- Spearheaded team-wide AI-assisted development: multi-agent model where a lead agent decomposed epics and delegated to sub-agents for implementation, tests and review, with shared prompt templates and guardrails — raising feature throughput by ~30%.
- Delivered a critical 2024 initiative MVP 2 weeks ahead of schedule; mentored 5 engineers, 2 promoted within the year.

Senior Front-End Developer

from 01.2022 to 06.2023 (1 year 6 months)
Medable, Дистанційно (IT)

Clinical trial & patient engagement platform, remote.
Stack: React, Next.js, TypeScript, GraphQL, AWS. HIPAA-compliant.

- Built and maintained a HIPAA-compliant patient portal used across 40+ clinical trials, serving 200,000+ patients.
- Integrated end-to-end encryption and role-based access control for sensitive (PHI) data in compliance with HIPAA and 21 CFR Part 11.
- Prepared release documentation and audit-trail reports together with compliance and QA teams.
- Led migration of a legacy jQuery dashboard to React / Next.js SSR, raising Lighthouse performance from 48 to 91.
- Implemented a configurable ePRO form engine (12 question types, conditional branching, multi-language).

Senior Front-End Developer

from 06.2019 to 12.2021 (2 years 7 months)
SoftServe, Дистанційно (IT)

Senior Front-End Engineer · Tech Lead. Client: Keller Williams — large-scale real estate platform, 50+ engineers.
Stack: React, React Native, GraphQL, AWS, TypeScript.

- Owned web dashboard architecture for KW Command — used by 180,000+ real estate agents globally.
- Migrated class components to React Hooks: −18% bundle size, test coverage 42% → 71%; SonarQube gates cut production bugs by 35%.
- Managed task breakdown, estimations and sprint planning for the frontend track; mentored 4 engineers (2 promoted).

Senior Front-End Developer

from 01.2018 to 05.2019 (1 year 5 months)
SoftServe, Дистанційно (IT)

Senior Front-End Engineer · Tech Lead. Client: Takeoff Technologies — warehouse operations cross-platform app, 25 engineers.
Stack: React Native, React, GraphQL, AWS.

- Defined frontend architecture for a warehouse operations app adopted across 12 grocery chains.
- Delivered Inventory Adjustment MVP in 3 months — chosen as proof-of-concept for a $50M global rollout.

Front-End Developer

from 08.2017 to 12.2017 (5 months)
Customer Times, Київ (IT)

Client: Carea Health — real-time communication app.
Stack: React Native, WebSocket, WebRTC, Twilio.

- Built real-time chat and video calls over WebSocket and WebRTC with <200ms latency under load.

Front-End Developer

from 07.2015 to 07.2017 (2 years)
K3-Soft, Київ (IT)

Projects: DIMO (Indonesian fintech mobile app, React Native) and MillionMind (EU gamification web app, React, Redux).

- Developed the DIMO fintech React Native app from scratch through App Store & Google Play launch in 8 months.
- Built core React/Redux frontend for MillionMind — a gamified quiz platform serving 100k+ users.

Education

Національний авіаційний університет (National Aviation University)

Electronics & Telecommunications, Київ
Higher, from 2011 to 2017 (6 years)

Master's Degree (магістр)

Additional education and certificates

IT

2015

Knowledge and skills

• Next.js
• React
• TypeScript
• JavaScript
• React Native
• Node.js
• Redux
• GraphQL
• REST API
• HTML
• Tailwind CSS
• Jest
• Playwright
• Webpack
• Storybook
• SQLite
• Git
• SQL
• AWS
• Stripe
• WebSocket
• AI prompting
• CSS

Language proficiencies

• Ukrainian — fluent
• English — above average
• Polish — average

Additional information

PROFESSIONAL SUMMARY
Senior Frontend / Full-Stack Engineer with 10+ years of experience building scalable web and mobile products in fintech, payments, regulated (HIPAA / 21 CFR Part 11) and high-load consumer domains. Founder and sole owner of trvl.best, where I designed and run a production payments stack across 4 providers (cards, crypto, Stripe, in-app subscriptions) with signed-webhook verification, idempotent processing, an append-only payments ledger, multi-currency normalisation, refunds and chargebacks. Most recently Frontend Engineer at EPAM Systems (Georgia) on a radio streaming platform, and previously Team Lead of an 8-engineer frontend team. For the last 2+ years I have worked AI-first: deep hands-on expertise in LLM integration, multi-agent engineering workflows and automation, and since April 2026 I teach AI courses for engineers. Known for owning products end to end — architecture, code, tests, security and release — with a strong focus on correctness, reliability and auditability.

WHY I FIT PAYMENTS / FINTECH
- Payment integrations in production: lava.top (cards, hosted checkout), Stripe, NOWPayments (crypto), RevenueCat (mobile in-app subscriptions) — checkout, renewals, cancellations, refunds, chargebacks.
- Money-safe engineering: HMAC-SHA256/SHA-512 webhook signature verification, idempotency keys & event de-duplication, replay-safe renewals, DB-level uniqueness guarantees, server-side price locking at checkout.
- Ledger & reconciliation: append-only payments journal, credit ledger (reserve → settle → refund), multi-currency → USD normalisation for revenue / ROAS reporting.
- Compliance & security mindset: HIPAA & 21 CFR Part 11 (audit trails, RBAC, E2E encryption), hosted checkout keeping card data out of scope (PCI DSS SAQ-A model), CSP, OAuth hardening, secret scanning in CI.
- Fintech product experience: shipped DIMO (Indonesian fintech) mobile app from scratch to App Store / Google Play.

TECHNICAL SKILLS
Core: React, Next.js (App Router, RSC), TypeScript, JavaScript (ES2023), HTML5 / Web APIs
Payments & FinTech: Stripe, lava.top, NOWPayments (crypto), RevenueCat, subscriptions & renewals, refunds / chargebacks, webhooks, idempotency, ledgers, multi-currency, promo & referral engines
Backend & Data: Node.js, Cloudflare Workers / Pages Functions, REST, GraphQL, SQL (SQLite / D1), migrations, KV, cron jobs, WebSocket, SSE
Security / Compliance: HMAC signatures, OAuth 2.0, RBAC, CSP / security headers, secret scanning, E2E encryption, HIPAA, 21 CFR Part 11, PCI DSS scope reduction
State & Styling: Redux Toolkit, React Query, Apollo Client, Tailwind CSS, Styled Components, CSS Modules, SASS
Testing: Vitest, Jest, React Testing Library, Playwright, Detox, TDD
Tooling & CI/CD: Vite, Webpack, Storybook, SonarQube, Datadog RUM, Sentry, GitHub Actions, CircleCI, Jenkins, AWS (Amplify, S3, Lambda), Firebase, React Native, Expo
AI / Automation: Anthropic Claude API, OpenAI API, Claude Code, Codex, Cursor, Copilot, multi-agent orchestration, prompt engineering, LLM cost / quota control, AI-assisted review & test generation

Portfolio: trvl.best
LinkedIn: [open contact info](look above in the "contact info" section)