Sebastian Luchian
I work on production e-commerce, SQL-backed business systems, REST APIs, caching, integrations, internal tools, and legacy .NET modernization.
Based in Iasi, Romania. Available from July 2026 for employment or B2B contract roles - .NET backend preferred, backend-focused full-stack accepted. Open to remote, hybrid, or relocation.
.NET developer
C# · ASP.NET · APIs · SQL
Production .NET systems
Backend work on live business applications
SQL-backed business logic
Queries, reporting, data access and issue analysis
Caching & state handling
Redis and CMS cache usage in production flows
Full-stack support
React/TypeScript when delivery needs it
Now
Open to .NET backend roles and B2B contract work.
Availability
Available from July 2026 for employment or B2B contract roles - backend preferred, backend-focused full-stack accepted.
Location
Based in Iasi, Romania. Open to remote, hybrid, or relocation-based work.
About
Backend .NET development for production business systems.
My strongest work is C#/.NET backend development, production debugging, data access, caching, integrations, and business logic, with React/TypeScript and CMS-backed UI delivery when needed.
- Professional software experience since 2022, mainly on production e-commerce and SQL-backed business systems.
- Strongest in C#/.NET backend development, production debugging, data access, caching, and business logic.
- Comfortable investigating TechOps/support-raised issues through logs, SQL, Redis/cache state, Application Insights, Postman, Ghost Inspector, and request-level analysis.
Experience
Backend .NET product work
.NET Developer focused on backend systems
.NET backend work across production e-commerce, SQL-backed business systems, REST APIs, caching, integrations, internal tools, legacy modernization, and practical full-stack delivery when needed.
Production engineering
- Worked on a live UK e-commerce/CMS platform built with ASP.NET, .NET Framework 4.8, SQL Server, Umbraco CMS, Redis, AngularJS, React, and Razor/CSHTML.
- Took ownership of production-critical tasks across backend investigation, SQL-backed issue analysis, release validation, customer-support escalations, and targeted fixes.
- Used Application Insights, logs, local debugging, database inspection, Postman, Ghost Inspector, and request-level analysis during dev-on-duty work.
- Improved cart workflows, Redis/Umbraco cache behavior, LINQ/SQL paths, and selected Entity Framework query patterns.
Delivery & business context
- Built back-office and reporting features, CSV exports, SQL views, marketing/engagement integration support, and external platform data flows for business users.
- Supported external API notifications and Stripe/NestJS subscription lifecycle flows.
- Supported releases and customer-support escalations while keeping release safety and business impact in mind.
Full-stack support when needed
- Built React/TypeScript features from Figma designs and bundled Webpack output into legacy ASP.NET/CSHTML views.
- Maintained AngularJS, jQuery, Razor/CSHTML, and CMS-backed interfaces connected to existing .NET functionality.
Projects
Backend systems, workflows, and product delivery
Selected work across production e-commerce, document workflows, operational reporting, SQL-backed logic, APIs, and business-facing backend systems.
Production e-commerce platform work involving cart and checkout workflows, subscription state, Redis/Umbraco cache issues, Stripe-related middleware flows, external API notifications, reporting, CSV exports, back-office tooling, and cart workflow improvements.
Support-to-release flow
Problem
Cart, checkout, CMS/admin, integrations, and reporting flows had to stay reliable under real customer and support pressure.
What I built
Investigated production issues through logs, Application Insights, SQL queries, Redis/Umbraco cache checks, Postman/Ghost Inspector validation, and targeted backend fixes.
Result
More reliable production flows, faster issue investigation, and safer changes in legacy .NET Framework code.
- .NET Framework 4.8 ·
- SQL Server ·
- Umbraco CMS ·
- Redis ·
- Stripe flows
- +5
Built a document workflow proof-of-concept from scratch with ASP.NET Core, PostgreSQL, EF Core, JWT authentication, permission-key authorization, audit history, reporting, batch attachments, and a React frontend. The system modeled department-based document routing with forward/back/complete/close actions and sensitive document access rules.
Workflow backend
Problem
Documents needed department-based routing, permission checks, attachments, reporting, and traceable workflow decisions.
What I built
Built an ASP.NET Core/PostgreSQL PoC with permission-key authorization, workflow actions, audit, reports, batch attachments, and React screens.
Result
Presented a client-facing proof-of-concept with a complete workflow model and working frontend.
- ASP.NET Core ·
- React ·
- PostgreSQL ·
- EF Core ·
- JWT
- +1
Built a tenant-aware ASP.NET Core backend prototype with PostgreSQL, EF Core, JWT refresh tokens, permission management, runtime configuration APIs, and a React admin UI. The project explored multi-tenant backend architecture, admin/runtime API separation, and config-driven runtime behavior.
Platform architecture
Problem
A backend platform needed separated admin/runtime concerns, tenant-aware behavior, permissions, and SQL-backed persistence.
What I built
Built a tenant-aware ASP.NET Core backend prototype with EF Core, JWT refresh tokens, permission management, runtime APIs, Docker, and a React admin UI.
Result
Demonstrates modular .NET backend design, admin/runtime API separation, persistence, and configuration-driven runtime behavior.
- .NET ·
- ASP.NET Core ·
- EF Core ·
- React ·
- TypeScript
- +1
Additional engineering work
Additional technical work
Smaller or more focused work that shows range across automation, systems, migration, and academic engineering projects.
Built Python collectors and a Flask reporting dashboard that centralized operational data from multiple external platforms. The system used APIs, Selenium crawlers, cron jobs, user management, reporting, and bonus/malus calculations to replace manual checking and provide unified month-to-month comparisons.
- Python ·
- Flask ·
- PostgreSQL ·
- Selenium ·
- Cron jobs ·
- Reporting
Worked on a PHP 7 to PHP 8 migration and implemented scoring logic for matching real estate offers against client preferences such as budget, area, rooms, and surface. Also handled UI bugfixes and compatibility issues caused by stricter PHP 8 behavior.
- PHP 7 ·
- PHP 8 ·
- MS SQL ·
- Scoring Logic ·
- Real Estate
Contributed to an NDA-covered enterprise medical/insurance workflow desktop application used by insurance operations teams. The system combined an Electron shell, Angular frontend, Java/Spring Boot microservices, REST APIs, PostgreSQL, MinIO-backed document storage, and XML-based document generation.
- Java ·
- Spring Boot 3 ·
- Angular ·
- Electron ·
- PostgreSQL ·
- MinIO
Worked on an industrial data collection/reporting project for a pipe production line. Collected PLC production data into SQL Server, built AVEVA/Wonderware screens and data views, and translated client requirements into reporting and data collection logic.
- AVEVA Wonderware ·
- Visual Basic ·
- MS SQL ·
- PLC Data
Worked on configuration-driven iGaming slot projects using C++, Python tooling, Excel math sheets, and RTP simulation workflows. Converted mathematician-provided game definitions into runtime configuration, validated behavior through simulations, and fixed configuration or game-related issues.
- C++ ·
- Python ·
- Game Logic ·
- RTP Simulation ·
- Slots
Academic SystemC project simulating packet routing across configurable router networks, including CPU-to-memory transactions, multi-router topologies, YAML-driven configuration, routing policies, and TTL handling.
- SystemC ·
- C++ ·
- CMake ·
- YAML ·
- Routing Simulation
How I think about backend systems
From business rules to production backend systems
I focus on backend systems where correctness, maintainability, data consistency, and production debugging matter.
Requirements, implementation, data, and production feedback
01
Product requirements
Business rules, support tickets, admin needs, edge cases
02
ASP.NET APIs
REST endpoints, validation, auth, integrations, webhooks
03
Business Services
Cart, checkout, workflows, reporting, admin operations
04
Data Layer
SQL Server, PostgreSQL, EF, LINQ, Redis/cache state
05
Production feedback
Logs, App Insights, Postman, Ghost Inspector, support follow-up
What I try to make visible in backend work
Traceability
Audit logs, request states, Application Insights traces, API checks, and reproducible support cases.
Data correctness
SQL-backed business rules, EF mappings, Redis/Umbraco cache checks, and regression-conscious fixes.
Operational feedback
Support tickets become debugging paths, targeted fixes, and release-safe improvements.
Tech
Tech stack
C# · .NET Framework · .NET · ASP.NET Core · REST APIs · JWT authentication · authorization · SQL Server · PostgreSQL · Entity Framework · EF Core · LINQ · SQL · Redis · caching · SQL/LINQ query tuning · React · TypeScript · AngularJS · JavaScript · Razor · CSHTML · jQuery · Webpack · Umbraco CMS · HTML · CSS · Git · Docker · Swagger/OpenAPI · Application Insights · Azure release support · Postman · JMeter · Ghost Inspector · Python · Flask · Selenium · BeautifulSoup · C++ · Java/Spring Boot basics
Backend
- C# ·
- .NET Framework ·
- .NET ·
- ASP.NET Core ·
- REST APIs ·
- JWT authentication ·
- authorization
Data
- SQL Server ·
- PostgreSQL ·
- Entity Framework ·
- EF Core ·
- LINQ ·
- SQL ·
- Redis ·
- caching ·
- SQL/LINQ query tuning
Web/CMS
- React ·
- TypeScript ·
- AngularJS ·
- JavaScript ·
- Razor ·
- CSHTML ·
- jQuery ·
- Webpack ·
- Umbraco CMS ·
- HTML ·
- CSS
Tools
- Git ·
- Docker ·
- Swagger/OpenAPI ·
- Application Insights ·
- Azure release support ·
- Postman ·
- JMeter ·
- Ghost Inspector
Other
- Python ·
- Flask ·
- Selenium ·
- BeautifulSoup ·
- C++ ·
- Java/Spring Boot basics
Certifications
Certifications & learning
NVIDIA Deep Learning Institute
Education
Engineering foundation & languages
Gheorghe Asachi Technical University of Iasi
Gheorghe Asachi Technical University of Iasi
Communication level
Available from July 2026 for employment or B2B contract roles - .NET backend preferred, backend-focused full-stack accepted. Open to remote, hybrid, or relocation-based work.
For .NET backend or backend-focused full-stack roles, contact me by email or LinkedIn.
[email protected]