Віктор

VICTOR FILINOVYCH
FULLSTACK DEVELOPER

SUMMARY
Full Stack JavaScript/TypeScript Developer with commercial experience building
MY CONTACTS production-grade backend systems and React frontends. Skilled in Node.js (Express,
NestJS), PostgreSQL, MongoDB, and integrating complex external APIs (Google Ads,
[open contact info](look above in the "contact info" section) Stripe, BigQuery, Telegram Bot). Strong focus on clean architecture, security, and
[open contact info](look above in the "contact info" section) automated testing.
Telegram
LinkedIn WORK EXPERIENCE
GitHub
Back-End Developer Jan 2026 – Aug 2026
Zhytomyr, Ukraine
Trading Systems Company (Remote)
Backend for an automated trading platform processing real-time market data from multiple
TECH SKILLS
exchanges.

• Node.js, Express, NestJS, TypeScript Implemented exchange API integrations (REST + WebSocket) with data validation and
normalization for market data feeds.
• PostgreSQL, MongoDB, Redis
Built monitoring, logging, and error tracking systems (Sentry) for production trading
• Prisma, TypeORM, Mongoose infrastructure.
• React, Redux Toolkit Wrote unit and integration tests for trading logic using Jest and Supertest.
• Docker, Docker Compose Worked with real-time WebSocket data streams, handling high-throughput event
• Git, Swagger/OpenAPI processing.
Contributed to order lifecycle tracking, balance and position management modules.
• JWT, OAuth2, AES-256-GCM
Used TypeORM for database migrations and schema management (PostgreSQL).
• Jest, Supertest, Mocha
Debugged production issues with clear reproduction steps and root cause analysis.
• WebSockets, REST API
Stack: NestJS, TypeScript, PostgreSQL, TypeORM, WebSockets, Jest, Supertest, Docker, Sentry
• Event-driven architecture
Back-End Developer Jan 2025 – Present
APIS & INTEGRATIONS Clck Fraud (Remote)
SaaS platform protecting advertising budgets by detecting bot traffic and blocking fraudulent
• Google Ads API, Meta API IPs across ad networks.
• Bing Ads API, BigQuery Built bot detection engine with 10+ fraud rules (real-time + batch): excessive clicks/min,
suspicious User-Agent, duplicate sessions, short sessions, low pageviews, abnormal visitor
• Google OAuth2, Analytics
ratios.
• Stripe, Mollie, PayPal
Designed heartbeat-based visit duration tracking (30-sec intervals via sendBeacon +
• Telegram Bot API beforeunload/visibilitychange), replacing unreliable 5-second timeout.
• Cloudinary Created dynamic script loader: single script tag replaces 170-line inline scripts. Hash-based
resolution, auto-updates with zero client changes, 5-min cache.

SOFT SKILLS Implemented IP blocking synced with Google Ads, Meta, and Bing APIs with retry logic for
failed syncs.

• Attention to detail Built blocked IP analytics: 7-day summary dashboard, drill-down with pagination. Optimized
raw SQL (COALESCE, COUNT DISTINCT).
• Decision making
Integrated Stripe (webhooks, subscriptions), Mollie (direct payments), PayPal (IPN). Invoice
• Clear communication generation with balance audit trail.
• Multitasking Implemented cookie-based JWT auth, Google OAuth2, Passport.js, AES-256-GCM token
encryption.
LANGUAGES Applied security hardening: Helmet, CORS, rate limiting, XSS filtering, Zod validation,
parameterized Prisma queries.
English C1 Stack: Node.js, Express, TypeScript, PostgreSQL, Prisma, Google Ads API, Meta API, Bing Ads API,
Ukrainian Native BigQuery, Stripe, Mollie, PayPal, Docker

Russian Fluent
Back-End Developer Aug 2024 – Sep 2025
Team Challenge (Volunteer Project) [GitHub]
EDUCATION
Community management platform for residential complexes with real-time communication.
Developed full REST API with 8 resource domains (25+ endpoints): auth, users, complexes,
GoIT — IT School
chat rooms, news, voting, notifications, contacts. Swagger/OpenAPI docs.
Fullstack Developer
2023 – 2024 Integrated Telegram Bot API (webhook-based) with state machine: login/logout, address
registration, broadcast notifications.

Zhytomyr Higher Military School of Radio Implemented JWT auth (1h access / 7d refresh), Google OAuth2, admin + per-complex
Electronics moderator roles.
Radio Engineer, diploma with honors Built voting system (single/multiple choice, anonymous, date-bounded), multi-language
1984 – 1989, 1992 – 1996 news (EN/UA) with emoji reactions.
Set up file upload pipeline: Multer → Cloudinary → auto-cleanup. Email service with HTML
templates.
Wrote integration tests with Mocha/Chai/Supertest.
Stack: Node.js, Express, MongoDB, Mongoose, Telegram Bot API, Cloudinary, JWT, Passport, Swagger

Co-founder / Engineer / Director Sep 2005 – Present
LLC Zhytomyrservicegroup (Engineering role: Apr 2018 – Aug 2023)

PROJECT EXPERIENCE
E-Pharmacy — Online Pharmacy Franchise Platform [GitHub] [Backend]
React, Redux Toolkit, Styled Components, Node.js, Express, MongoDB, JWT, Cloudinary
Full-stack e-commerce. Shop management, product CRUD with Cloudinary, statistics
dashboard, JWT auth with role-based access, responsive design.

Psychologists Services — Psychologist Directory [GitHub]
React, Redux Toolkit, Firebase Auth, Material-UI
Firebase auth, multi-criteria sorting, favorites system with Redux Persist, responsive Material-UI
layout.

Read Journey — Personal Reading Tracker [GitHub]
React, Redux Toolkit, Styled Components, Axios
Book discovery with pagination, personal library with status tracking, reading diary with session
logs and statistics, responsive design.