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Contact SERHII DOBROVOLSKYI
Location: Ukraine · Remote SOFTWARE ENGINEER — T-SQL / MICROSOFT SQL SERVER ·
Email: [открыть контакты](см. выше в блоке «контактная информация») DELPHI (OBJECT PASCAL) · PYTHON BACKEND
Telegram: @sergey_dobrovolskj
LinkedIn: [открыть контакты](см. выше в блоке «контактная информация») PROFILE
dobrovolskyi-62622b27a
GitHub: github.com/dsvsergey Software Engineer with 25+ years of commercial experience building
enterprise systems, databases, and backends. 16+ years of Microsoft SQL
Key Skills Server / T-SQL and Delphi (Object Pascal) — developing the business logic of
an enterprise system at Kirovohradoblenergo (Stored Procedures, Functions,
Microsoft SQL Server / T-SQL — Triggers, Views, query optimization and indexing) plus Delphi / C++ desktop
Stored Procedures, Functions, clients. 10+ years of Python backend (FastAPI, Flask, Django) — high-load
Triggers, Views, complex SQL REST APIs, async processing, ETL, and external-service integrations. Modern
queries (JOINs, subqueries, CTEs, experience with AI (LangChain / LangGraph, OpenAI API), FastAPI, ETL,
window functions), Query integrations, and Docker. Delphi / Object Pascal is a direct path to the Pascal-like
Optimization, Execution Plans, C/AL of Navision / Dynamics NAV. Open to T-SQL / SQL / ERP developer and
Index Optimization, SQL Python Backend roles.
refactoring, database schema
design
KEY ACHIEVEMENTS
Languages & Enterprise
Development — Delphi / Object • 16+ years of Microsoft SQL Server / T-SQL development — Stored
Pascal (16+ years), C / C++ (C+ Procedures, Functions, Triggers, Views, complex queries, performance tuning
+Builder, Visual C++ MFC), C# / (Execution Plans) and indexing within an enterprise system at
VB.NET; enterprise business Kirovohradoblenergo
systems, business logic,
• 16+ years of Delphi / Object Pascal — from enterprise desktop systems to
automation, ERP-style solutions
the Delphi client of a commercial platform still in production
Python Backend & API — Python • Sole developer of BZBToolbox — a commercial e-commerce content-
(FastAPI, Flask, Django), REST management platform, in intensive production use for 8+ years
API & WebSocket, async
• Migrated a legacy C + Informix system to Frappe / ERPNext (PostgreSQL)
programming (asyncio),
• Designed and maintained a production database (90+ tables, 100K+ records)
microservices, high-load backend
with SQL rule engines and stored procedures
systems, task queues (Redis,
RabbitMQ)
Databases & Data — PostgreSQL,
WORK EXPERIENCE
MySQL / MariaDB, MongoDB,
Informix (migration), SQLAlchemy + BZBGEAR — Backend / Database Engineer, Sole Developer of
Alembic, SQL, ETL/ELT, indexing, BZBToolbox
query optimization 2016 – present · Full-time Software Developer (2016–2023) · Full-time Contractor
ERP & Integrations — Frappe / (2023–2026) · Part-time Contractor (2026–present)
ERPNext, legacy → ERP migration, • Sole developer of BZBToolbox, a commercial content-management platform
custom DocTypes; marketplace & (Flask backend with SQLAlchemy/Alembic, MySQL → MariaDB, Delphi client)
CRM integrations (WooCommerce, — built end-to-end and still in intensive production use
X-Cart, eBay, Amazon, Newegg,
• Designed and maintained the production database (90+ tables, 100K+
Zoho CRM), Google Maps API
records); built SQL rule engines, stored procedures, and multi-stage SQL,
AI (applied) — OpenAI API, and optimized heavy queries
LangChain, LangGraph, RAG, • Built and maintains the platform's Delphi client (Object Pascal)
prompt engineering, async AI
• Developed services to automatically list/update products, brands, and
workflows (FastAPI)
categories on marketplaces (X-Cart, WooCommerce) via REST APIs; built
Infrastructure — Docker, Docker exchange-file processing for eBay/Amazon/Newegg; integrated Zoho CRM
Compose, Git, CI/CD, Linux • Built the platform's AI content service (FastAPI, SQLAlchemy, PostgreSQL,
(production) LangChain/LangGraph, OpenAI API)
 • Implemented a Redis-based background task queue and automated database
Education backups to Google Cloud Storage
• Developed web scrapers (Selenium, Playwright) and a Django internal app
Specialist Degree in Systems
Engineering Logool Corp — Backend Engineer (Contract)
Central Ukrainian National May 2026 – June 2026
Technical University • Migrated a legacy C + Informix system to Frappe / ERPNext on PostgreSQL
1994 – 1999 — DocType design, business-logic and data migration

Independent Backend Engineer — Freelance
Languages
2023 – present
• Ukrainian — native
• Built a mobile-app backend (REST API) on FastAPI + SQLAlchemy +
• English — working proficiency PostgreSQL for a Canadian fitness company (Docker); a Flask bank-statement
automation app for the RoboCode school (payment allocation, Alembic
migrations)
• Worked with RabbitMQ and MongoDB; developed web scrapers / parsers for
data collection

DipDev Studio — Flutter / Backend Engineer, Dart (Contract)
Jan 2024 – Jul 2024
• Built Flutter clients and a Dart backend for controlling networked BZBGEAR-
brand PTZ cameras (real-time video) — delivered for BZBGEAR by
arrangement

VBto Converter — Software Engineer (freelance, long-term project)
2008 – 2016
• Built code-conversion and data-processing tools in Delphi, C/C++ (C+
+Builder, Visual C++ MFC), and C#/VB.NET; maintained and supported
legacy systems

Kirovohradoblenergo — Software Engineer (Programmer)
2000 – 2016 · full-time
• Developed and maintained an enterprise business system for the energy
company — Microsoft SQL Server back end, Delphi / C++ desktop clients
• Implemented business logic in T-SQL: Stored Procedures, Functions,
Triggers, Views
• Wrote and optimized complex SQL queries; analyzed Execution Plans and
tuned indexing to improve performance
• Performed legacy T-SQL refactoring and maintained the database schema
as the system evolved
• Built enterprise applications and automation in Delphi / Object Pascal and C/
C++; later in Python