Mykola Varenyk
AVP, Senior Software Developer
Praha
Summary
Results-driven Backend-Focused Software Engineer with over 14 years of experience, including more than 7 years in the FinTech sector at Barclays. Expertise in Risk Management, Market Pre-Trade, and Treasury systems, complemented by a proven track record in developing scalable, high-performance services using C# .NET, RESTful APIs, and SignalR for real-time communication. Proficient in event-driven architectures with Solace and Blazor for creating interactive dashboards, along with extensive experience in multiple database technologies such as MSSQL, PostgreSQL, Oracle, and MySQL. Skilled in implementing containerized deployments on OpenShift (Kubernetes) using Docker and Helm to enhance operational efficiency.
Overview
16
16
years of professional experience
Work History
AVP, Software Engineer
Barclays
09.2018 - Current
- Domain: FinTech – Risk Management, Market Pre-Trade, Treasury
- Design and implement RESTful APIs connecting front-office trading systems with risk analytics platforms, handling 10,000+ daily requests with sub-200ms latency – critical for pre-trade risk checks.
- Architect backend services and data integration pipelines for Treasury and Risk Management systems, improving system throughput by 35%.
- Leverage Solace event broker for low-latency message streaming between pre-trade risk engines, enabling real-time risk calculations before trade execution.
- Develop full-stack Blazor Server applications for real-time risk monitoring dashboards, replacing legacy Excel-based reporting and reducing data retrieval time by 60%.
- Implement real-time SignalR hubs to push live pre-trade risk alerts and treasury updates to trader dashboards with sub-second latency (100+ concurrent users).
- Work extensively with MSSQL and Oracle databases – design schemas, write complex T-SQL/PL/SQL, optimize stored procedures for low-latency risk calculations.
- Deploy and configure backend services to OpenShift using Docker, Helm charts, rolling updates, and blue-green deployments for zero-downtime releases.
- Lead backend code quality initiatives including API versioning and performance optimization, reducing production incidents by 25%.
- Mentor 3 junior developers on .NET Core, Blazor, SignalR, database optimization, and OpenShift deployments.
C# .NET / Backend Developer
EPAM Systems
03.2013 - 09.2018
- Designed and maintained backend services and RESTful APIs supporting risk management desktop applications, enabling seamless data exchange between multiple internal systems.
- Built reusable backend modules and data access layers following clean architecture principles, reducing code duplication by 30%.
- Worked with MS SQL Server and PostgreSQL – designed database schemas, wrote optimized queries, and implemented Entity Framework (EF6/EF Core) for data access.
- Integrated backend services with front-end WPF clients using asynchronous patterns and efficient data serialization (JSON/XML).
- Partnered with business analysts to translate complex requirements into scalable backend specifications with 99.5% on-time delivery.
- Championed Agile best practices across two backend-focused development teams.
C# .NET Backend Developer
Codeminders / Tristero Consulting
10.2011 - 01.2013
- Developed backend integration solutions and RESTful-style APIs for VoIP systems, enabling interoperability between 5+ disparate telephony platforms.
- Built server-side call routing and data synchronization services handling 10,000+ monthly call events.
- Used MySQL for data persistence, including schema design and query optimization.
- Created WPF client GUI as a consumer of backend VoIP services, following MVVM and Prism modularity.
- Used TortoiseSVN for version control and JIRA for backend issue tracking, reducing bug resolution time by 35%.
C# .NET Backend Developer
Cognito Informationssysteme GmbH
01.2010 - 11.2011
- Implemented data access layers and business logic in C# .NET, integrating with Infragistics for front-end reporting.
- Developed data access layers and business logic in C# .NET, facilitating integration with Infragistics for front-end reporting.
- Used MS SQL Server for data storage, including writing stored procedures and managing indexing for performance.
- Conducted backend bug fixing, refactoring, and unit testing, enhancing data consistency and system stability.
- Managed version control using Visual SourceSafe, ensuring code integrity and collaboration.
Education
High School Diploma -
Cherkasy National Technological University
Ukraine 04.2001 -
Skills
Languages & Frameworks: C#, NET Framework, NET Core, ASPNET Core, Minimal APIs, Microsoft Blazor, SignalRAPI & Communication: RESTful API design, OpenAPI (Swagger), Web Services, Integration Pipelines, Server-Side Logic, Event-Driven Architecture, Real-Time WebSockets
Messaging & Streaming: Solace (PubSub, Event Broker, Queues, Topics)
Databases: MSSQL (SQL Server), PostgreSQL, Oracle, MySQL, T-SQL, PL/SQL, Stored Procedures
ORMs & Data Access: Entity Framework, ADONET
Desktop & GUI: WPF, WinForms, MVVM, Prism, Infragistics NetAdvantage, DevExpress
Testing: xUnit, NUnit, Moq, Unit Testing, Integration Testing
Version Control: GitLab, Git, TortoiseSVN
Containers & Orchestration: OpenShift (Kubernetes), Docker, Helm, Containerization, Rolling Updates, Blue-Green Deployments
Tools & Methodologies: Agile (Scrum), JIRA, Refactoring, GitLab CI/CD
AI Coding: Codex and Gemini AI Studio
Timeline
AVP, Software Engineer
Barclays
09.2018 - Current
C# .NET / Backend Developer
EPAM Systems
03.2013 - 09.2018
C# .NET Backend Developer
Codeminders / Tristero Consulting
10.2011 - 01.2013
C# .NET Backend Developer
Cognito Informationssysteme GmbH
01.2010 - 11.2011
High School Diploma -
Cherkasy National Technological University
04.2001 -