Siarhei Vasilyeu

Sr. Software Developer, Product Management & Delivery at Ontario Health

Extended Azure-hosted ASP.NET application with SQL Server/SSRS to onboard new healthcare providers. Analyzed backend data model to enforce integrity and security rules. Designed and implemented an Azure Data Factory pipeline for file retention and reworked preprocessing to SQL Server to mitigate nested loop issues. Automated CI/CD for SSRS reports to Power BI, replacing manual steps. Built a bulk-upload utility for Entra user attributes and led a POC to migrate SSRS reports to Power BI and embed paginated reports in an ASP.NET MVC app.

Platform Technical Lead at Bank of Montreal (BMO)

Designed and implemented end-to-end telephony migration from Genesys to AWS Amazon Connect, aligning with new business requirements. Reverse-engineered undocumented message flows to map contracts between the customer contact center system and Genesys, enabling reliable interoperability with Amazon Connect. Established end-to-end debugging (Genesys Softphone) for IVR use cases, reducing data flow by 80% by filtering non-critical events. Created system design documents and integration diagrams for incorporating IBM MQ telephony events into the .NET codebase; applied Mediator pattern to route MQ events and ensure SOLID extensibility. Authored Confluence documentation for IVR use cases and inbound/outbound JSON message prototypes to speed onboarding.

Sr. Software Developer, Tech Lead at Bank of Montreal (BMO)

Migrated large system from .NET Framework to .NET Core to resolve cold-start delays; analyzed logs, extended inline classes to SOLID standards, updated incompatible libraries, and expanded unit tests. Replaced reflection with expression trees and optimized object cloning. Refactored WCF services to align with newer .NET types and validated changes with end-to-end tests; documented environment setup and added developer guides; increased test coverage and stability.

Lead Developer, Architect at IBM Canada

Led design of cloud-native, event-driven microservices for banking platform on Azure. Evaluated Azure components (Event Hub, Service Bus) via POCs and defined deployment patterns. Established coding standards (OOP, SOLID), CI/CD practices (ARM templates, branching, code reviews), and an Observer-based workflow for cross-service exception handling. Implemented Azure security with OIDC and managed identities; introduced xUnit-based testing and SonarQube quality gates.

Sr. .NET/SQL Consultant (Full-Stack) at Tangerine Bank

Performed design reviews and pre-production performance analysis for Tangerine.ca; reduced API/database latency by eliminating inefficient queries. Analyzed SQL Server indexing, removing large volumes of unused non-clustered indexes to restore stability under peak load. Debugged Java modules and in-line queries; built a performance toolkit for Angular SPA and outlined a UI load-testing plan to reduce TTFB from >2s to under 500ms.

Sr. Consultant at Just Energy Group

Led CRM performance initiative after reported slow responses; optimized non-clustered indexes, implemented async/multithreaded processing, caching, service throttling, and DB pool tuning. Managed large ETL imports (5M+ accounts, 100M+ transactions), introduced chunked synchronization and bulk loads to complete within 24 hours. Developed Angular diagnostics to monitor ETL processes and automated multi-environment deployments with Octopus Deploy.

Team Lead, Architect at Olson Canada

Led development of Ontario’s OESP web portals under tight governance; established CI/CD with Visual Studio Online, GIT, and Octopus Deploy. Designed core workflow engine using asynchronous C#, DI, and EF with Unit of Work; implemented robust SQL Server design and SSDT-based deployment. Facilitated daily SCRUMs and aligned Canadian/U.S. teams on tools and milestones, improving sprint velocity by 20–30%.

Sr. Software Developer at PWC/TCS

Modernized a high-visibility survey web app with UI/UX enhancements, implemented HTML5 localStorage caching to reduce server round-trips, and conducted cross-browser tuning. Gathered requirements and translated them into design documents; performed cross-browser testing to maintain layout consistency and introduced upgrade strategies using HTML5 features and client-side validation.

Sr. Software Developer at Just Energy Group

Led development of a vendor-facing CRM platform exposing secure WCF endpoints; implemented custom bindings for SSL offloading, throttling, and MTOM; optimized SQL Server databases with SSDT and tuning tools; automated builds/releases with Octopus Deploy; produced API documentation and integration guides for external partners.

Sr. .NET Developer at ONYX Enterprise Solutions

Contributed to a financial planning ASP.NET app; built interactive UI components with jQuery; integrated SSRS and OpenXML reporting using a Strategy pattern; developed tax calculation modules and leveraged EF with Repository/Unit of Work for maintainable data access.

Sr. Web Developer at TDSB (Toronto District School Board)

Designed ASP.NET and Oracle DB components for ministry suspension reports; built UI data filtering by demographics; supported data reporting initiatives and data migrations; collaborated with DBAs to identify data gaps.

Web Developer at Metroland Digital Media

Designed and developed ASP.NET modules for Wheels.ca, Goldbook.ca, Deals4U.ca; created custom ImageUploader control; wrote advanced SQL procedures to optimize site search and performance; managed deployment and server optimization.

Web Services Developer at Purolator Courier Ltd.

Architected xPurolator Excel VSTO solution to batch-process Purolator e-ship services; developed VSTO UI components and integrated tools to improve development productivity; provided technical consulting for other initiatives and delivered stakeholder presentations.

Software Developer at Bank of Montreal (BMO)

Developed diagnostics and maintenance utilities to troubleshoot database, SMTP, SFTP, and other system components; created deployment strategies and conducted unit testing on XML outputs; produced design/deployment docs and supported release activities.

.NET Software Developer at Canadian Medic Alert

Migrated code from CRM 5.7 to 6.0; reverse-engineered business logic and GUI objects; integrated multiple business objects to support CRM workflow; collaborated with stakeholders for UAT and production deployment.

Software Developer at Bank of Montreal (BMO)

Designed ASP.NET intranet web application for back-office operations; implemented UI components, security model enhancements, and data-driven UI elements; supported SDLC and deployment efforts.

Software Developer at CallWiz Integrated Solutions Inc.

Designed workflow components for a Medical Office Management app; gathered requirements, drafted use cases, identified opportunities for process optimization; redesigned and extended the relational database model to support XML-based data processing.

Sr. Software Developer at Husky Injection Molding Systems Ltd

Upgraded ASP.NET 2.0 app and SQL Server schema; designed service layer components with SOAP/XML messaging; led spike research on MS CRM 4.0 and .NET extensions; coordinated Agile migration and deployment.

.NET Software Developer at Dhamma Torana Centre

Built client registration management web services, data processing parsers for TXT/XML/CSV, and implemented composeable workflows for data handling; researched data management strategies and reusable components.