Олег

OLEG OLEFIRENKO
[відкрити контакти](див. вище в блоці «контактна інформація») [відкрити контакти](див. вище в блоці «контактна інформація») Ukraine

Summary
Senior MS SQL Developer with solid experience in database development, architecture, and performance
optimization. Strong expertise in T-SQL, MS SQL Server, good skills in PostgreSQL, There is also experience
in DWH, BigQuery development, proficiency in SSIS, SSAS, SSRS, PowerShell tools. Some experience with c#,
Node.js, Delphi.
Constant experience designing and optimizing large-scale, distributed database environments, working
with databases containing a lot of records and high-volume ETL processes. Alse constant Skilled in
troubleshooting complex technical and architectural issues, database redesign, and continuous performance
improvement.

Work Experience
2020 – Present Trinetix
Senior MS SQL Developer
Project: Global enterprise risk management and data analytics platform for a Big 4
client. The solution supports risk assessment and audit-related processes across
multiple regions and countries. The ecosystem also includes a centralized Data
Warehouse (DWH) and Data Mart used for reporting, analytics, data integration,
and data exchange with external systems.
Responsibilities:
Design and development of MS SQL databases for a large-scale enterprise
•

platform operating across multiple regions and countries.
Development and maintenance of T-SQL solutions, including stored procedures,
•

functions, views, triggers, tables, indexes, and complex queries.
Database architecture and design, including schema design, normalization,
•

indexing, and continuous system optimization.
Extensive SQL performance optimization, covering queries, stored procedures,
•

database structures, and ETL processes.
Analysis and resolution of architectural and technical issues, including
•

debugging and optimization of existing database solutions.
Development and optimization of ETL processes for a centralized Data
•

Warehouse, processing up to hundreds of thousands of records per load.
Development and support of a Data Mart for reporting and analytics, including
•

data synchronization and integration with external systems.
Worked with distributed databases across multiple countries, with the largest
•

tables containing millions of records.
Continuous redesign and rearchitecture of the platform and Data Mart to
•

support evolving business requirements and improve performance.
Used Microsoft Copilot to support SQL development and code analysis, including
•

work with large-scale procedures and database structures.

2013 – 2019 EPAM Systems
MS SQL, C#, Node.JS Developer
Developed and supported an audit management system for a large banking
•

organization.
Designed and developed MS SQL databases and T-SQL solutions.
•

Worked on database performance optimization and troubleshooting.
•

Designed and maintained SSIS processes for data integration and processing.
•

Worked with C# and Node.js as part of application development and supported
•

project delivery.

2011 – 2013 B2B SOFT
Programmer and Customer Support Administrator
Administration and support of 1,500+ client MS SQL databases.
•

Database development and maintenance using T-SQL, SSIS, and OLAP in an MS
•

SQL Server 2008 R2 environment.
SQL Server performance monitoring and optimization, including query analysis
•

and troubleshooting.
Administration of replication, mirroring, backup, security, linked servers, jobs,
•

and database maintenance.

2009 – 2011 STIROL
Software Development Unit Head
Led a software development team and coordinated delivery of internal
•

automation projects.
Designed and implemented an MS SQL-based reporting system using SSRS.
•

Automated workflows across 10+ organizational sites in Ukraine, integrating
•

them with a central head office.

2008 – 2009 SE “UKRPATENT”
Project Manager
Managed the development and implementation of an HR management system.
•

Coordinated development of the solution using MS SQL Server 2008 R2 and
•

Delphi.
Oversaw project delivery, requirements, implementation, and support.
•

2006 – 2008 FOZZY GROUP
Principal Programmer / Project Manager
Led development and implementation of internal software solutions using MS
•

SQL Server, Delphi, and C#.
Managed software development projects from requirements through
•

implementation.
Designed database-driven solutions and coordinated development activities.
•

2003 – 2006 Different projects
Software Developer / Project Developer

Education
Master program: Automated Control Systems
National Technical University of Ukraine 'Kyiv Polytechnic Institute'
Faculty: Information and Computer Science Field of specialization: DBMS, project management. Application
programming, automation of production processes.

Technical Skills
Databases: MS SQL Server, PostgreSQL, MySQL
•

Database Development: T-SQL, Database Design, SQL Performance Optimization, SSIS, SSAS, OLAP
•

DBA: MS SQL Server Administration, Replication, Mirroring, Backup & Recovery, Security, Monitoring
•

Programming: Delphi (10+ years), C# (1+ years), Node.js (1+ year), PowerShell
•

Tools & Version Control: Git, Bitbucket, SVN, TFS, Perforce, Jira, Mantis
•

Leadership: Team leadership and coordination of software development teams of up to 5 people
•

Project Experience: Enterprise software development and implementation across HRM, reporting,
•

workflow automation, loyalty programs, and business applications
English: A2+ spoken, confident written communication
•