Mykola K.

I build production backends and scrapers that stay stable under load. I have migrated legacy systems, scaled APIs beyond 3,000 active users and 7M+ records, and built async data pipelines that process about 35,000 businesses in 9 minutes for roughly $0.25 in compute. I also build custom scrapers and crawling pipelines that turn dynamic and protected websites into structured data. If you need someone who owns the backend and reliably extracts data from the web, I focus on performance, failure cases, anti bot systems, and cost from day one. What I do, backend and APIs: • Design and build REST APIs with FastAPI and Django, sync and async • Architect microservices and background processing with Celery, Redis, Kafka, RabbitMQ • Implement secure authentication with JWT, OAuth2, Argon2id, Supabase Auth, and role based access • Optimize databases with PostgreSQL, SQLAlchemy, Supabase, Redis caching, and query tuning • Integrate payments and webhooks with Stripe and other providers • Deliver clean, tested, maintainable code What I do, web scraping and automation: • Build Python scrapers with requests, BeautifulSoup, Selenium, Playwright, Scrapy, undetected chromedriver, proxy rotation • Handle both simple static sites and JavaScript heavy SPAs • Bypass anti bot measures including Cloudflare, reCAPTCHA, hCaptcha and similar shields • Use undetected headless browsers, 2captcha and CapSolver, and human like behavior to stay under the radar • Scrape social platforms and restricted APIs, including Twitter via TwiKit and reverse engineered endpoints • When there is no public API, extract data directly from the web Asynchronous and scalable crawling: • Use asyncio, aiohttp, asyncio.gather and asyncio.Lock for high volume scraping • Crawl thousands of pages concurrently for e commerce price monitoring and large scale data collection • Run long lived workflows with attention to efficiency and stability Data processing and delivery: • Clean and structure results into CSV, Excel, JSON, or direct database writes • Integrate outputs into existing systems or dashboards • Set up scheduled jobs so your data stays up to date Applied AI and automation: • Integrate OpenAI models such as GPT 4, GPT 4o mini, and GPT 5 mini into real products • Build scoring, classification, and enrichment pipelines with Langfuse observability • Add AI on top of ETL for cleaning, deduplication, routing, prioritization, and decision logic • Implement chatbots, assistants, and business intelligence features powered by LLMs • Embed GPT or custom models into scraping flows to classify content, auto fill forms, and make on the fly decisions Selected results, influencer discovery API (Instagram, TikTok, YouTube): • Migrated the service from Flask to FastAPI with a full sync to async refactor • Recovered many previously broken endpoints and platforms • Scaled the system to more than 7M database records and around 3,000 active users • Added Celery task queues on Redis and GPT based content scoring with Langfuse monitoring Selected results, Google Maps business intelligence backend: • Processes about 35,000 businesses in 9 minutes using two level async parallelism • Uses aiohttp, asyncio.gather and asyncio.Lock to avoid race conditions and keep the database stable • Includes JWT and OAuth2 auth, Argon2id password hashing, a simple CRM for contacts and follow ups, and CSV export Previous projects: • Django REST backends with Stripe payments, webhooks, and admin tools • Automation and scraping systems with Selenium, Playwright, undetected chromedriver, rotating proxies, 2captcha and CapSolver • Backend automation for Web3 and social platforms with Discord and Twitter API integrations Tech stack I am confident owning: • Backend: Python 3.10+, FastAPI, Django, Flask, Django REST Framework • Async and messaging: asyncio, aiohttp, Celery, Redis, Kafka, RabbitMQ • Databases: PostgreSQL, Supabase, SQLite, SQLAlchemy ORM • Auth and security: JWT, OAuth2, Argon2, Supabase Auth, cryptography • AI and monitoring: OpenAI API, Langfuse, OpenTelemetry • Scraping and automation: requests, BeautifulSoup, Selenium, Playwright, Scrapy, undetected chromedriver, TwiKit, 2captcha, CapSolver, proxy infrastructure • DevOps: Docker, Docker Compose, GitHub Actions, Linux You should contact me if: • You need a backend for an AI product, SaaS platform, data heavy API, or large scale scraping system • You want to migrate from Flask or legacy Django views to FastAPI or DRF with async where it actually helps • You want AI powered scoring, enrichment, or automation built directly into your backend and scrapers • You care about clean, maintainable code with tests, clear structure, and predictable behavior If you have a concrete problem, send me a short description and I will tell you what I can build for it and how I would approach it.