Senior Data Engineer/DBA at Amaryllis
Illinois, United States
Oleg Marushchak
Council Member
Oleg Marushchak is a Senior Data Engineer with over 21 years of experience managing, optimizing, and securing complex enterprise data environments across the United States, Israel, and Ukraine. Based in Chicago, Illinois, he specializes in cloud data platforms, high-availability database systems, and performance tuning for mission-critical enterprise applications.
Currently, Oleg Marushchak serves as a Snowflake Data Engineer at Sutton Bank in Attica, Ohio, a position he has held since November 2025. In this role, he develops and maintains the Snowflake database structure supporting the bank's payment operations, designing and documenting database schemas while writing and debugging stored procedures to optimize query performance. He builds and manages data pipelines using the Snowflake cloud data platform with AWS S3 storage layers, collaborating on architecture design to meet the functional requirements of the Payments department. He establishes backup, recovery, and disaster prevention procedures to ensure data continuity, creates and maintains database objects including tables, views, stored procedures, and user-defined functions, and produces monthly and quarterly reports while maintaining the Sutton Bank Data Lineage tool. His work ensures compliance with Bank Secrecy Act, Anti-Money Laundering regulations, USA PATRIOT Act, and OFAC requirements.
From May 2024 to November 2025, Oleg Marushchak worked as a Senior Data Engineer, Database Engineer, and DBA at Amaryllis Payment Solutions in Herzliya, Israel, on a contract basis. He independently stabilized a large and complex legacy database codebase without knowledge transfer, mitigating serious operational and financial risks during an organizational transition. He designed and implemented an advanced Databricks-based architecture for transaction alert processing, resulting in substantial improvements in scalability, performance, and cost efficiency. He designed a novel large-scale data lifecycle management solution enabling the removal and archival of large data volumes without downtime on a 24/7 platform, and presented this high-availability data archive solution at SQL Saturday in Orlando, sharing insights with the professional database engineering community. He migrated enterprise workloads to Databricks and Azure SQL with minimal downtime, built ETL pipelines with SSIS and CDC to process structured and semi-structured data in Databricks, and administered and tuned high-volume OLTP and Data Warehouse SQL Server instances on-premises and on Azure VM. He implemented backup and disaster recovery using SSMS and PowerShell, configured Always On Availability Groups, automated maintenance tasks including backups, reindexing, and deployments via PowerShell, and participated in candidate selection, onboarding, and structured knowledge transfer to the newly formed technical team.
Prior to that, Oleg Marushchak served as a Senior Data Engineer at EPAM Systems in Kyiv, Ukraine, from July 2021 to May 2024 on a contract basis. He developed data architecture in Snowflake by designing schemas and database objects including tables, views, streams, tasks, and external tables, enabling efficient data processing and integration. He tuned Snowflake and Azure SQL Databases for performance, cost, and availability, designed data models, and implemented ELT pipelines using Azure Data Factory. He built scalable workflows using Azure Data Lake, Logic Apps, Cosmos DB, and Azure Functions, and optimized queries and data architecture in Snowflake, enhancing performance and reducing computational costs. He migrated Clover-based ETL to Azure Data Factory and improved monitoring and CI/CD for ADF and SQL.
From June 2020 to July 2021, Oleg Marushchak worked as a Database Engineer at Trinetix Inc in Sheridan, Wyoming. He developed and optimized T-SQL procedures and schemas in Azure SQL Database, designed and optimized database schemas, tables, and indexes to enhance data storage, retrieval, and performance, and built Azure Functions integrated with ASP.NET Core-based applications.
Oleg Marushchak worked as a Database Engineer at Regional Gas Company in Kyiv, Ukraine, from November 2019 to May 2020. He designed, developed, and optimized SQL Server Data Warehouses including ETL and ELT processes using SSIS, developed and deployed OLAP cubes using SSAS, and designed reports using SSRS. He managed the migration of a one-billion-record database from MySQL to MS SQL Server with minimal downtime.
Currently, Oleg Marushchak serves as a Snowflake Data Engineer at Sutton Bank in Attica, Ohio, a position he has held since November 2025. In this role, he develops and maintains the Snowflake database structure supporting the bank's payment operations, designing and documenting database schemas while writing and debugging stored procedures to optimize query performance. He builds and manages data pipelines using the Snowflake cloud data platform with AWS S3 storage layers, collaborating on architecture design to meet the functional requirements of the Payments department. He establishes backup, recovery, and disaster prevention procedures to ensure data continuity, creates and maintains database objects including tables, views, stored procedures, and user-defined functions, and produces monthly and quarterly reports while maintaining the Sutton Bank Data Lineage tool. His work ensures compliance with Bank Secrecy Act, Anti-Money Laundering regulations, USA PATRIOT Act, and OFAC requirements.
From May 2024 to November 2025, Oleg Marushchak worked as a Senior Data Engineer, Database Engineer, and DBA at Amaryllis Payment Solutions in Herzliya, Israel, on a contract basis. He independently stabilized a large and complex legacy database codebase without knowledge transfer, mitigating serious operational and financial risks during an organizational transition. He designed and implemented an advanced Databricks-based architecture for transaction alert processing, resulting in substantial improvements in scalability, performance, and cost efficiency. He designed a novel large-scale data lifecycle management solution enabling the removal and archival of large data volumes without downtime on a 24/7 platform, and presented this high-availability data archive solution at SQL Saturday in Orlando, sharing insights with the professional database engineering community. He migrated enterprise workloads to Databricks and Azure SQL with minimal downtime, built ETL pipelines with SSIS and CDC to process structured and semi-structured data in Databricks, and administered and tuned high-volume OLTP and Data Warehouse SQL Server instances on-premises and on Azure VM. He implemented backup and disaster recovery using SSMS and PowerShell, configured Always On Availability Groups, automated maintenance tasks including backups, reindexing, and deployments via PowerShell, and participated in candidate selection, onboarding, and structured knowledge transfer to the newly formed technical team.
Prior to that, Oleg Marushchak served as a Senior Data Engineer at EPAM Systems in Kyiv, Ukraine, from July 2021 to May 2024 on a contract basis. He developed data architecture in Snowflake by designing schemas and database objects including tables, views, streams, tasks, and external tables, enabling efficient data processing and integration. He tuned Snowflake and Azure SQL Databases for performance, cost, and availability, designed data models, and implemented ELT pipelines using Azure Data Factory. He built scalable workflows using Azure Data Lake, Logic Apps, Cosmos DB, and Azure Functions, and optimized queries and data architecture in Snowflake, enhancing performance and reducing computational costs. He migrated Clover-based ETL to Azure Data Factory and improved monitoring and CI/CD for ADF and SQL.
From June 2020 to July 2021, Oleg Marushchak worked as a Database Engineer at Trinetix Inc in Sheridan, Wyoming. He developed and optimized T-SQL procedures and schemas in Azure SQL Database, designed and optimized database schemas, tables, and indexes to enhance data storage, retrieval, and performance, and built Azure Functions integrated with ASP.NET Core-based applications.
Oleg Marushchak worked as a Database Engineer at Regional Gas Company in Kyiv, Ukraine, from November 2019 to May 2020. He designed, developed, and optimized SQL Server Data Warehouses including ETL and ELT processes using SSIS, developed and deployed OLAP cubes using SSAS, and designed reports using SSRS. He managed the migration of a one-billion-record database from MySQL to MS SQL Server with minimal downtime.
From July 2012 to October 2019, Oleg Marushchak served as Principal DBA and Developer at Niva Pereyaslavshchiny LLC in the Kyiv region, Ukraine. He led the IT department and developed an in-house ERP system covering grain accounting, livestock, and retail operations. He implemented and maintained high availability solutions including Always On Availability Groups to ensure 24/7 uptime, managed database security including user permissions, access control, and data encryption, and provided 24/7 on-call support for critical database systems, resolving production issues and minimizing downtime.
From August 2009 to June 2012, Oleg Marushchak worked as Principal DBA and Developer at Golden Foods Group in Kyiv, Ukraine. He designed the ERP backend on SQL Server 2008 R2 for snack manufacturing operations and delivered a full reporting stack via SSRS while fine-tuning transactional performance.
Earlier in his career, from August 2007 to August 2009, Oleg Marushchak served as Lead DBA and Database Developer at Inter Trans Police Insurance Company in Kyiv, Ukraine. He administered SQL Server 2008 and created an insurance accounting system with schema, procedures, and SSIS-based ETL.
From May 2004 to April 2007, Oleg Marushchak worked as Principal Developer at United Silo Company LLC in Kyiv, Ukraine. He invented and deployed a grain accounting system across more than 30 grain elevators and built a centralized corporate database for agriculture coordination.
Oleg Marushchak holds multiple certifications including Microsoft Certified: Fabric Analytics Engineer Associate (DP-600), Microsoft Certified: Azure Data Engineer Associate (DP-203), Microsoft Certified: Azure Data Fundamentals (DP-900), Databricks: Lakehouse Fundamentals, and Snowflake: Hands-On Essentials – Data Warehouse.
From August 2009 to June 2012, Oleg Marushchak worked as Principal DBA and Developer at Golden Foods Group in Kyiv, Ukraine. He designed the ERP backend on SQL Server 2008 R2 for snack manufacturing operations and delivered a full reporting stack via SSRS while fine-tuning transactional performance.
Earlier in his career, from August 2007 to August 2009, Oleg Marushchak served as Lead DBA and Database Developer at Inter Trans Police Insurance Company in Kyiv, Ukraine. He administered SQL Server 2008 and created an insurance accounting system with schema, procedures, and SSIS-based ETL.
From May 2004 to April 2007, Oleg Marushchak worked as Principal Developer at United Silo Company LLC in Kyiv, Ukraine. He invented and deployed a grain accounting system across more than 30 grain elevators and built a centralized corporate database for agriculture coordination.
Oleg Marushchak holds multiple certifications including Microsoft Certified: Fabric Analytics Engineer Associate (DP-600), Microsoft Certified: Azure Data Engineer Associate (DP-203), Microsoft Certified: Azure Data Fundamentals (DP-900), Databricks: Lakehouse Fundamentals, and Snowflake: Hands-On Essentials – Data Warehouse.