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Contact SERHII DOBROVOLSKYI
Location: Ukraine · Remote PYTHON BACKEND ENGINEER — FASTAPI, SQLALCHEMY,
Email: [открыть контакты](см. выше в блоке «контактная информация») POSTGRESQL & INTEGRATIONS
Telegram: @sergey_dobrovolskj
LinkedIn: [открыть контакты](см. выше в блоке «контактная информация») PROFILE
dobrovolskyi-62622b27a
GitHub: github.com/dsvsergey Backend engineer with 10+ years building production, data-intensive systems in
Python. I was the sole developer of BZBToolbox, a commercial e-commerce
Key Skills content-management platform (Flask backend, MySQL→MariaDB, Delphi client)
still in production — including marketplace/CRM integrations and an AI content
Backend & API — Python
service on FastAPI + PostgreSQL. I design scalable, fault-tolerant backend
(FastAPI, Flask, Django), REST
systems on FastAPI, SQLAlchemy, and PostgreSQL — schema design and
API and WebSocket design, async
optimization, async processing (asyncio), high-load REST APIs, ETL, and
programming (asyncio),
external-service integrations (Google Maps API, CRM, marketplaces). I have
microservice architecture, high-load
experience building mobile-app backends and working with geodata and GPS
backend systems, task & message
coordinates. Recently migrated a legacy C + Informix system to Frappe/ERPNext
queues (Redis, RabbitMQ)
on PostgreSQL. Open to Backend / Senior Backend / API roles.
Data & Databases — PostgreSQL,
MySQL / MariaDB, MongoDB,
KEY TECHNICAL ACHIEVEMENTS
Informix (migration), SQLAlchemy +
Alembic (ORM & migrations), SQL
• Sole developer of BZBToolbox — a commercial e-commerce content-
(complex queries, window
management platform, in intensive production use for 8+ years
functions, CTEs), schema design,
• Migrated a legacy C + Informix system to Frappe/ERPNext on PostgreSQL
indexing, query optimization, stored
procedures, ETL/ELT pipelines • Migrated the BZBToolbox database from MySQL to MariaDB (90+ tables,
100K+ records)
Automation & Integrations —
• Optimized heavy, multi-stage SQL (CTEs, temporary tables) for high-load
Web scraping (Selenium,
processing
Playwright), marketplace & CRM
integrations (WooCommerce, X- • Built an automated cloud-backup system for databases and files to Google
Cart, eBay, Amazon, Newegg, Zoho Cloud Storage
CRM), Google Maps API, geodata /
GPS coordinates, Google Cloud SELECTED PROJECTS
Storage, rule engines
ERP — Frappe Framework, AI Content Service — BZBToolbox
ERPNext, legacy → ERP migration, • FastAPI + SQLAlchemy + PostgreSQL service using LangChain/LangGraph
custom DocTypes, workflow and the OpenAI API to generate SEO-ready product content (titles,
automation descriptions, meta tags, feature lists, specs) from scraped supplier data; async
AI (applied) — OpenAI API, LLM (asyncio) at catalog scale; Flutter web client
integration, LangChain, LangGraph, • Python · FastAPI · SQLAlchemy · PostgreSQL · asyncio · LangChain ·
RAG, prompt engineering, async AI LangGraph · OpenAI API
workflows (FastAPI)
Market Intelligence & Lead-Generation System — BZBGEAR
Desktop & Media — PySide6,
• Combined official US population statistics, geographic (GPS) coordinates, and
OpenCV, Flutter/Dart, real-time
Google Maps API data to identify promising clients and regions; built a GPS-
video / camera control
coordinate lead-finding tool
Infrastructure — Docker, Docker
• Python · Google Maps API · GPS / geodata · SQL · data analysis
Compose, Git, CI/CD, Linux
(production)
Education WORK EXPERIENCE
Specialist Degree in Systems
BZBGEAR — Backend Engineer / Sole Developer, BZBToolbox
Engineering
2016 – present · Full-time Software Developer (2016–2023) · Full-time Contractor
Central Ukrainian National
(2023–2026) · Part-time Contractor (2026–present)
Technical University
• Sole developer of BZBToolbox, a commercial content-management platform
1994 – 1999
(Flask backend with SQLAlchemy/Alembic, MySQL → MariaDB, Delphi client)
— built end-to-end and still in intensive production use today
Languages
• Designed and maintained the production database (90+ tables, 100K+
• Ukrainian — native records); built SQL rule engines, stored procedures, and multi-stage SQL, and
• English — working proficiency optimized heavy queries for high-load processing
• Migrated the platform database from MySQL to MariaDB
• Implemented a Redis-based background task queue for the BZBToolbox
backend
• Developed services that automatically list and update products, brands, and
categories on marketplaces (X-Cart, WooCommerce) via REST APIs, with
CRUD and data validation
• Built exchange-file processing and generation between eBay, Amazon,
Newegg, and NeweggBusiness; integrated Zoho CRM with BZBToolbox
• Built the platform's AI content service (FastAPI, SQLAlchemy, PostgreSQL,
LangChain/LangGraph, OpenAI API) and desktop PTZ-camera control
systems (Python, PySide6, OpenCV)
• Built an automated backup system for databases and files to Google Cloud
Storage
• Built a lead-generation tool that finds prospective clients by GPS coordinates
using the Google Maps API
• Built a US region-analysis system based on official population statistics,
geographic coordinates, and the Google Maps API to identify promising
markets and prospective clients
• Developed web scrapers and data-collection automation using Selenium and
Playwright
• Developed a Django app for internal needs

Logool Corp — Backend Engineer (Contract)
May 2026 – June 2026
• Migrated a legacy C + Informix system to Frappe/ERPNext on PostgreSQL

Independent Backend Engineer — Freelance
2023 – present
• Built a mobile-app backend (REST API) on FastAPI + SQLAlchemy +
PostgreSQL for a Canadian fitness company; containerized with Docker
• Built a Flask bank-statement automation app for the RoboCode school
(statement ingestion, payment allocation to student accounts); database
migrations with Alembic
• Worked with RabbitMQ (inter-service messaging) and MongoDB (document
store) on freelance projects
• Developed web scrapers / parsers for data collection and automation
DipDev Studio — Flutter / Backend Engineer, Dart (Contract)
Jan 2024 – Jul 2024
• Built Flutter clients and a Dart backend for controlling networked BZBGEAR-
brand medical PTZ cameras (real-time video) — delivered for BZBGEAR by
arrangement

VBto Converter — Software Engineer
2008 – 2016
• Developed backend logic and data-processing tools in Delphi, C/C++ (C+
+Builder, Visual C++ MFC), and C#/VB.NET; maintained and supported legacy
systems