Роман

Roman Sytnik
Full-Stack .NET Developer
Email: [відкрити контакти](див. вище в блоці «контактна інформація») Phone: [відкрити контакти](див. вище в блоці «контактна інформація») Location: Lviv, Ukraine LinkedIn: roma-sytnik GitHub: xrstdx

Professional Summary

Full-stack .NET developer with 2+ years of commercial experience building production SaaS systems across video
intercom management, enterprise support ticketing, and an email-based CRM. Strong backend focus - designing
domain models, CQRS/ES pipelines, multi-tenant authorization, and external integrations - with solid front-end
capability in React and Vue 3. Comfortable owning features end-to-end: from database schema and API design
through to the UI and CI/CD deployment.

Technical Skills

Backend C# · .NET 6/7/8 · ASP.NET Core · Entity Framework Core · CQRS · Event Sourcing
· MediatR · SignalR · Hangfire · FluentValidation · AutoMapper · xUnit
Frontend TypeScript · Vue 3 · Vue 2 · React 18 · Pinia · Vuex · Vite · TailwindCSS · Vuetify
· WebRTC
Databases SQL Server · EF Core Migrations · Azure Event Store
Cloud & DevOps Azure · Docker · GitHub Actions · Bitbucket Pipelines

Work Experience

Full-Stack Developer - Oski November 2023 – April 2026
Remote

Main backend contributor across production systems, owning complete feature cycles from schema design through
API implementation to frontend integration.

Email-based CRM & Webmail Client
Email-based CRM built for a client to manage company communications with external contacts. Stack: .NET 8 · ASP.NET
Core · React 18 · TypeScript · Azure AD · Microsoft Graph API · Azure OpenAI · Azure Event Store · Azure Blob

• Implemented semantic search using Azure OpenAI embeddings - built a custom immutable vector index with
slot recycling for deleted entries, deferred async writes, and support for negative query vectors ("similar to X
but not Y")
• Built a per-entity permission system: access control enforced on every request via a base controller action
filter with Azure AD identity resolution
• Built a standalone CLI tool for rebuilding the embedding index from scratch, used for admin maintenance
without touching the main application
• Delivered various business-driven features including React 18 SPA components, background workers, and
API endpoints across the full stack

Enterprise Helpdesk & Support Ticketing SaaS
Multi-module platform covering ticket lifecycle, customer management, scheduling, and third-party integrations for field
service businesses. Stack: .NET 6 · ASP.NET Core · EF Core 6 · SQL Server · SignalR · Vue 2 · TypeScript ·
MailKit

• Owned and fully built the permission system from scratch - a role/permission matrix with a custom autho-
rization attribute, covering all resource types across the application
• Rearchitected file storage across the entire project - replaced base64 strings in the database with a two-stage
upload/commit service; abstraction allows swapping to cloud storage without code changes
• Built dynamic forms end-to-end: schema storage, form builder UI, and submission handling with custom
field types including signature capture and file upload
• Implemented in-app notifications and live Kanban board updates - both delivered via real-time push to
connected clients
• Extended the calendar module with additional event and scheduling types to cover new business workflows
• Delivered various business-driven features across the stack including API endpoints, Vue components,
integrations, and background services

Real-Time Video Intercom SaaS
Multi-tenant platform for managing video intercom systems in residential and commercial properties. Stack: .NET 7 ·
ASP.NET Core · EF Core 7 · SQL Server · SignalR · Hangfire · Vue 3 · Pinia · TypeScript · Docker

• Implemented sequential resident calling - when a visitor rings, residents are called one by one with config-
urable ring windows; escalation to the next resident is scheduled via Hangfire
• Rearchitected file storage with the same two-stage upload/commit abstraction - supporting both local and
S3-compatible backends via a feature flag
• Conducted high-load testing using NBomber: wrote scenarios simulating concurrent users to identify bottle-
necks before production release
• Performed end-to-end call testing with Puppeteer and a custom Node.js WebRTC client that initiated real
video calls to validate the full calling flow under automated conditions
• Delivered various business-driven features across the platform including access control, background workers,
and API endpoints in response to changing client requirements
• Containerised the full stack with Docker and configured GitHub Actions CI/CD pipelines for backend and
frontend

Education

Bachelor of Science - Computer Science 2018 - 2022
Ivan Franko Lviv National University · Lviv, Ukraine

Languages

Ukrainian Native
English Upper Intermediate (B2)