
Siarhei Charniak engineered robust backend solutions across core Folio repositories, notably mod-data-export and mod-inventory, focusing on multi-tenant data integrity, export reliability, and workflow automation. He delivered features such as partial PATCH updates for inventory records, concurrency-safe export statistics, and enhanced cross-tenant MARC data handling, using Java, SQL, and the Spring Framework. His approach emphasized maintainable code quality, introducing static analysis, refactoring for clarity, and comprehensive test automation with Karate and integration tests. By aligning API design with business needs and improving CI/CD pipelines, Siarhei ensured scalable, resilient services that reduced manual intervention and improved operational transparency.
February 2026 monthly summary: This period focused on delivering robust partial update capabilities across the inventory domain, strengthening data integrity for instances and items, and improving development workflows and export correctness. Key work spanned API and storage layers across three repositories, with measurable business value in reduced manual data fixes, safer partial updates, and faster release cycles.
February 2026 monthly summary: This period focused on delivering robust partial update capabilities across the inventory domain, strengthening data integrity for instances and items, and improving development workflows and export correctness. Key work spanned API and storage layers across three repositories, with measurable business value in reduced manual data fixes, safer partial updates, and faster release cycles.
January 2026: Strengthened multi-tenant data integrity in folio-integration-tests by adding automated validation for deleted records harvesting. Delivered targeted tests to ensure single-tenant deletion status is correctly reflected across consortia setups, aligning with MODOAIPMH-637. Overall, the work improved test coverage, reduced risk of data drift, and supports reliable multi-tenant data lifecycles.
January 2026: Strengthened multi-tenant data integrity in folio-integration-tests by adding automated validation for deleted records harvesting. Delivered targeted tests to ensure single-tenant deletion status is correctly reflected across consortia setups, aligning with MODOAIPMH-637. Overall, the work improved test coverage, reduced risk of data drift, and supports reliable multi-tenant data lifecycles.
December 2025: Delivered robust enhancements to ECS Data Export in folio-org/mod-data-export, focusing on multi-tenant robustness, handling of deleted records, metadata integrity, and cross-tenant sharing. Implemented workflows to export both actual and deleted MARC records, enabled downloading shared instances from member tenants, and improved the data client resilience across tenants. Fixed critical issues related to export state 'deleted' and expanded coverage with multi-tenant enhancements, improving data completeness, accuracy, and cross-tenant collaboration. Result: higher reliability, faster onboarding for multi-tenant customers, and clearer auditability.
December 2025: Delivered robust enhancements to ECS Data Export in folio-org/mod-data-export, focusing on multi-tenant robustness, handling of deleted records, metadata integrity, and cross-tenant sharing. Implemented workflows to export both actual and deleted MARC records, enabled downloading shared instances from member tenants, and improved the data client resilience across tenants. Fixed critical issues related to export state 'deleted' and expanded coverage with multi-tenant enhancements, improving data completeness, accuracy, and cross-tenant collaboration. Result: higher reliability, faster onboarding for multi-tenant customers, and clearer auditability.
November 2025: Delivered reliability and data integrity enhancements for holdings export in folio-org/mod-data-export. Implemented fixes for export accuracy and statistics in large jobs, refactored holdings ID slicing for reliable exports, and included temporary holdings location data to improve data representation and usability in large export jobs. These changes improve data quality, reduce post-export fixes, and support downstream analytics.
November 2025: Delivered reliability and data integrity enhancements for holdings export in folio-org/mod-data-export. Implemented fixes for export accuracy and statistics in large jobs, refactored holdings ID slicing for reliable exports, and included temporary holdings location data to improve data representation and usability in large export jobs. These changes improve data quality, reduce post-export fixes, and support downstream analytics.
October 2025 monthly summary focusing on reliability improvements for data export statistics under concurrency in folio-org/mod-data-export. Implemented a thread-safe fix to ensure accurate 'Failed' statistics for large export jobs and validated through testing. The work reduces risk of under/over-reporting and improves confidence in operational metrics and SLAs.
October 2025 monthly summary focusing on reliability improvements for data export statistics under concurrency in folio-org/mod-data-export. Implemented a thread-safe fix to ensure accurate 'Failed' statistics for large export jobs and validated through testing. The work reduces risk of under/over-reporting and improves confidence in operational metrics and SLAs.
Month: 2025-09 — Mod Data Export: Code Quality and Documentation Improvements. Delivered foundational quality improvements to the folio-org/mod-data-export module, enabling proactive quality gates and reducing maintenance risk. Implemented static analysis readiness and documentation updates to support long-term stability of the data export workflow. Key actions include enabling the checkstyle plugin, updating Javadoc, and a targeted refactor pass to improve readability and maintainability.
Month: 2025-09 — Mod Data Export: Code Quality and Documentation Improvements. Delivered foundational quality improvements to the folio-org/mod-data-export module, enabling proactive quality gates and reducing maintenance risk. Implemented static analysis readiness and documentation updates to support long-term stability of the data export workflow. Key actions include enabling the checkstyle plugin, updating Javadoc, and a targeted refactor pass to improve readability and maintainability.
Concise monthly summary for 2025-08 highlighting key features delivered, major bugs fixed, overall impact, and technologies demonstrated across folio-org/mod-fqm-manager, folio-org/mod-lists, and folio-org/mod-data-export-worker. Delivered measurable business value through relational data exposure, data type normalization, and refactoring strategic configurations management. Notable outcomes include improved data integrity, scalable maintenance, and enhanced security controls, contributing to faster inventory decisions and reduced incident risk.
Concise monthly summary for 2025-08 highlighting key features delivered, major bugs fixed, overall impact, and technologies demonstrated across folio-org/mod-fqm-manager, folio-org/mod-lists, and folio-org/mod-data-export-worker. Delivered measurable business value through relational data exposure, data type normalization, and refactoring strategic configurations management. Notable outcomes include improved data integrity, scalable maintenance, and enhanced security controls, contributing to faster inventory decisions and reduced incident risk.
July 2025 monthly summary focusing on delivering reliability and business value through improved test coverage, workflow integrity, and advanced query capabilities across core Folio projects.
July 2025 monthly summary focusing on delivering reliability and business value through improved test coverage, workflow integrity, and advanced query capabilities across core Folio projects.
June 2025 monthly summary focused on improving correctness and reliability of authority records export validation in folio-org/mod-data-export. Implemented targeted fixes to the validation flow for CQL exports, removing a redundant CSV-format check and clarifying error handling when the default authority job profile is not used. This reduced false positives in export validation and improved data quality for downstream cataloging workflows.
June 2025 monthly summary focused on improving correctness and reliability of authority records export validation in folio-org/mod-data-export. Implemented targeted fixes to the validation flow for CQL exports, removing a redundant CSV-format check and clarifying error handling when the default authority job profile is not used. This reduced false positives in export validation and improved data quality for downstream cataloging workflows.
December 2024: Focused on reliability and multi-tenant error handling in the mod-data-export workflow. Delivered stability improvements for large exports and enhanced error handling for Central-tenant scenarios, with clearer logging and selective omission of inaccessible tenant records. Release 5.1.3 consolidates these fixes and marks production readiness.
December 2024: Focused on reliability and multi-tenant error handling in the mod-data-export workflow. Delivered stability improvements for large exports and enhanced error handling for Central-tenant scenarios, with clearer logging and selective omission of inaccessible tenant records. Release 5.1.3 consolidates these fixes and marks production readiness.
November 2024 performance summary focusing on delivering observability, multi-tenant context safety, and release engineering across three Folio projects. Key features delivered include enhanced observability and context handling, with a stable data export pipeline release.
November 2024 performance summary focusing on delivering observability, multi-tenant context safety, and release engineering across three Folio projects. Key features delivered include enhanced observability and context handling, with a stable data export pipeline release.

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