Roman

Roman Ozirskyi Barcelona
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.NET Backend Engineer
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.NET Backend Engineer with 3+ years building high-load SaaS and SKILLS

fintech/trading platforms (200K+ API calls/day, 99.5% uptime).
Merged contributor to Microsoft EF Core (PR #37492) — working at Core: C#​, .​NET ​Core ​6+​, .​NET ​
the framework level gives me deep insight into .NET internals and Framework ​4.​8+​, ASP.​NET ​Core, EF
performance optimization that goes beyond typical application work. ​Core, Clean ​Architecture, CQRS,
Specialized in Clean Architecture, CQRS, distributed systems, and MediatR, DDD
observability at scale.
High-Load & Observability: Redis,
Polly, OpenTelemetry, Grafana,
WORK EXPERIENCE Prometheus, Docker, Kubernetes

Other: PostgreSQL, SQL ​Server,
Ethereal Core RabbitMQ, Azure ​DevOps,
Remote • 03/2026 - Present Terraform, TDD/​xUnit, SOLID, Git,
.NET Backend Developer JWT, ML.​NET
Full-time

• Designed and architected the full backend for SEO Desk Language: English ​C1, Ukrainian ​
(seodesk.io) SaaS platform (200k API calls/day, 99.5% uptime) Native, Spanish ​A2
using .NET 8, Clean Architecture and CQRS.
• Reduced feature onboarding time by 30%, external call errors by EDUCATION
35%, and sync backlog by 50% with Redis, Polly, and parallel
processing.
Bachelor in Computer
• Implemented Google OAuth2, Strategy+Factory for GSC reports, Science
offset pagination, and high-load optimizations (cold-start <1s,
Brotli compression –65%).
WSEI UNIVERSITY
Lublin
• Deployed Docker containers on Railway with PostgreSQL and
Redis.
CERTIFICATIONS

Quantitative Strategies Group LLC Advanced ML.NET &
Remote • 06/2025 - 03/2026 Predictive Analytics
.NET Backend Developer 09/2025
Full-time

• Led architectural overhaul of microservices for trading systems: Domain-Driven Design in
introduced Vertical Slice + CQRS with MediatR (+30% developer Practice
velocity). 04/2023
Pluralsight
• Architected AI-powered Strategic Analytics microservice (ML.NET)
and Event Sourcing with Marten (anomaly detection +22%,
reconciliation –50%).
.NET/C# Advanced
• Established observability (OpenTelemetry, Grafana, Prometheus), 01/2022
IaC (Terraform), and reduced dashboard latency by 35% with IT Step
Redis HybridCache.
• Improved peak throughput by 28% and reduced external failures
by 27% with Polly and TPL Dataflow.
Stealth startup
Remote • 10/2024 - 04/2025
.NET Backend Developer
Full-time

• Took ownership of .NET backend for early-stage US booking
platform for small businesses.
• Implemented CQS architecture, JWT auth, Stripe payments with
webhooks, and core booking domain APIs.
• Standardized pagination/filtering with custom LINQ and
contributed to TypeScript/React frontend.
• Established efficient cross-functional workflow, reducing
integration issues.

Early-Stage Startups
Remote • 09/2022 - 09/2024
.NET Backend Developer
Full-time

• Built multiple backend projects for small clients using .NET 6,
Clean Architecture, EF Core, JWT and REST APIs (booking
systems, internal tools, data services).
• Gained strong foundation in modern .NET practices, caching,
background services and unit testing.

OPEN SOURCE CONTRIBUTIONS

Microsoft • 01/2026 - Present
.Net developer • Remote

• Contributed to the official Microsoft EF Core repository by
implementing provider-internal fixes for SQLite integration,
improving type handling and value binding to prevent runtime
mapping errors.
• Authored and expanded comprehensive unit tests for type-
binding edge cases, increasing provider test coverage by 18% and
significantly reducing regression risk.
• Actively participated in the project workflow: reviewed pull
requests, provided feedback, and ensured contributions met high
standards of correctness, maintainability, and adherence to EF
Core guidelines.
• Successfully published and merged PR: #37492 Impact: Resolved
critical type-binding issues and enhanced interoperability
between SQLite provider and EF Core internals for all
downstream applications.