Ruslan

RUSLAN KLYMENKO
Python Backend Developer | Rivne, Ukraine
[open contact info](look above in the "contact info" section) | Telegram: t.me/klymenkorus
LinkedIn: [open contact info](look above in the "contact info" section) | GitHub: github.com/KLYMENKORUS

SUMMARY
Passionate Python Backend Developer with 3+ years of experience, building everything from automation
scripts to business solutions through clean code and thoughtful design. Skilled at knowledge sharing and
collaborative problem-solving, while staying highly self-organized even under pressure. I believe effective
communication and teamwork are the key to any project’s success: I enjoy discussing architecture, welcome
constructive criticism, and care about harmony within the team. Open to new challenges and eager to grow with
a development team, I see every task as a chance to sharpen both my technical and soft skills.

TECHNICAL SKILLS
• Languages: Python (asyncio, OOP), SQL
• Backend Frameworks: FastAPI, Django, Celery, RabbitMQ, REST API, Pydantic, Pydantic
AI, Data validation, Background workers (Celery)
• Databases & Caching: PostgreSQL, MongoDB (Indexing, Aggregation Pipelines, Sharding, complex
queries), Redis, SQLAlchemy (ORM), Alembic (migrations)
• Scraping & Data Extraction: Web Scraping, Playwright, aiohttp, lxml, Anti-bot bypass (Proxy
rotation, fingerprint masking, CAPTCHA handling, User-Agent & header rotation, Rate-limit & retries)
• AI Tools: LLM, OpenAI API, Pydantic AI, Claude Code
• Frontend: Streamlit
• DevOps & Cloud: Git, Bitbucket, Linux (bash, systemd), Docker, docker-compose, Nginx, VPS
Deployment, CI/CD, uv
• Testing & Quality: Architecture, Systems Design, SOLID, Code Review, pytest, pytest-asyncio, ruff
(linting)

EXPERIENCE
Python Backend Developer Oct 2023 - Oct 2026
Targer Rivne, Ukraine

Project key: Haggly E-commerce Platform
Led the development, extension and maintenance of parsers for 11 e-commerce sources, and built a REST API
for extracting and serving this data. Maintained documentation, introduced automated tests, and kept product
data in the database accurate and up to date according to business logic through heavy Celery-based
background workers, covering 2M+ products.

Responsibilities & Accomplishments:
• Developed and maintained parsers for 11+ e-commerce sources, performing continuous source analysis and
adapting extraction logic using Playwright, aiohttp, and lxml to handle frequent website redesigns and
selector changes.
• Built and maintained a REST API using FastAPI, handling continuous extraction and updates for 2M+
products across the database.
• Improved the quality and accuracy of parsed product data from 50% to 80% through advanced
multi-source data aggregation, ensuring all details and prices mapped correctly for seamless end-user
display.

• Overcame MongoDB’s 16 MB single-document size limit by re-architecting complex nested catalog
structures into optimized sub-documents to implement stable catalog updates.
• Built robust anti-bot bypass solutions for blocked sources: dynamic proxy rotation, request
header/fingerprint handling, and advanced retry strategies.
• Maintained and evolved the logic of heavy Celery background workers for continuous price
synchronization, stock checks, and updates, reducing stale product records by approximately 90%.
• Wrote custom SQL queries to select and prepare product data for analytics.
• Maintained and extended business logic for updating products and their subcategories.
• Designed advanced MongoDB indexes and wrote complex aggregation pipelines and queries to speed up
data retrieval and updates.
• Deployed and operated background workers that refreshed data from sources automatically.
• Built an admin panel for mapping filters, using AI to display correct filters to end users.
• Authored technical documentation and introduced automated tests using pytest to improve platform
reliability.

Project key: Slyd
Developed and maintained backend architecture for a real-time brand-mention monitoring platform using
FastAPI, Celery, RabbitMQ, MongoDB, and Redis, processing 500,000+ daily social media posts and
web articles across 200+ active client campaigns 24/7.

Responsibilities & Accomplishments:
• Designed and maintained asynchronous data-collection pipelines for TikTok, YouTube, Threads, and
200+ news sources, improving mention detection latency from 15+ minutes down to 1-2 minutes.
• Handled up to 300K+ background tasks per day with high stability, zero downtime, and robust fault
tolerance.
• Resolved recurring scraping failures caused by IP bans, rate limits, TLS fingerprinting, and Cloudflare by
implementing proxy rotation, session pooling, and browser automation using Playwright, curl cffi, and
aiohttp, increasing extraction success rates from 65% to 98.5%.
• Optimized distributed task processing by separating workloads into prioritized RabbitMQ queues and
configuring dedicated Celery workers, eliminating backlogs during traffic spikes.
• Implemented Redis-based caching and deduplication to prevent repeated processing, reducing redundant
MongoDB writes by approximately 40%.
• Set up, deployed, and optimized MongoDB on VPS environments, keeping databases responsive under
high concurrent load via custom indexes and complex aggregation pipelines.
• Maintained REST API endpoints, investigated production errors, and managed Linux-based services using
Docker Compose, Nginx, and systemd.
• Mentored junior team members, performed code reviews, and streamlined continuous release pipelines.

EDUCATION
Bachelor’s Degree in Transportation Process Management, Ukrainian State Railway Academy 2018 -
2021

LANGUAGES
• English: B1 Intermediate (Professional Working Knowledge)
• Ukrainian: Native