👋 Hi, I’m Alex — a .NET backend engineer who turns complex workflows into maintainable software.

I build APIs, integrations, and self-hosted applications with C# and .NET. I enjoy the parts where software meets reality: legacy systems, authentication, unreliable connections, background jobs, and data that needs to stay correct.

My recent personal work focuses on passwordless identity, multi-tenant applications, and reusable infrastructure.

🚀 What I’m Building

🔐 D3AuthServer

A standalone passwordless identity platform for connecting my applications through a shared sign-in system.

• OpenID Connect with OpenIddict, Authorization Code flow, and PKCE.
• Passkeys, magic links, and trusted-device approvals with number matching.
• Per-service access grants, session management, audit trails, and a reusable .NET client library.

🏠 Family Organizer

A household management application connecting shared finances, shopping, receipts, inventory, schedules, and meal planning.

• A multi-tenant modular monolith with explicit module boundaries.
• Household isolation enforced on database reads and writes.
• Background processing through a transactional outbox, with integration tests against PostgreSQL.

🏢 BuildingManagementApp

A condominium management application built around how Greek apartment buildings actually operate.

• Monthly expense workflows connecting building managers, accounting offices, and residents.
• Reconciliation, versioned statements, payments, maintenance, and assembly voting.
• .NET 10, Angular, and EF Core with SQLite and PostgreSQL support.

🤖 AIAgentApp

A modular .NET library for embedding AI agents into applications.

• Pluggable skills, MCP tools, memory, and scheduled tasks.
• Email workflows and structured extraction from receipts and documents.
• Application-specific policies and approval controls, with agent runtime data separated from host application data.

🖥️ DotNetDesk-Server

A self-hosted server implementation in C#/.NET targeting compatibility with unmodified RustDesk clients.

• Rendezvous and relay services, plus a web administration console.
• Device management, shared address books, access policies, and audit logs.
• Ongoing work on protocol compatibility, deployment, and end-to-end validation.

🏥 Integration Background

My MedTech work includes ORMService, a configurable HL7-to-database mapper built over raw TCP sockets, using reflection and JSON mapping definitions.

I’ve also built Windows services and APIs for:

• Uploading laboratory results to national platforms through REST and SOAP.
• Turning complex ERP data into medical referral payloads.
• Ingesting HL7 messages and mapping them into EF Core models.
• Queuing email and SMS notifications with System.Threading.Channels and Polly.

⚓ At Marpoint

I work on company-owned maritime connectivity and management systems, contributing to backend APIs, shared data-access components, authentication, and integrations.

This includes extending existing services, investigating issues across repositories, and maintaining compatibility with legacy components. These are team projects at my current employer.

🛠️ Tech Stack

• Core: C#, .NET / ASP.NET Core, SQL, Entity Framework Core
• Web & desktop: TypeScript, Angular, Blazor, MudBlazor, Avalonia, .NET MAUI
• Identity: OpenID Connect, OAuth 2.0, OpenIddict, WebAuthn / passkeys
• Data: PostgreSQL, SQL Server, SQLite, MariaDB, LiteDB
• Integrations: TCP/IP, HL7, REST, SOAP, MQTT, SignalR, MCP
• Operations: Linux, Docker, Nginx, systemd, Azure DevOps, WireGuard
• Testing: xUnit, integration tests, Playwright

🧠 How I Build

I care about explicit boundaries, useful logs, recoverable failures, and tests that exercise real behavior.

Build it like someone’s going to depend on it.
Secure it like someone’s going to attack it.
Simplify it like you’ll be maintaining it at 3 AM.

📫 Want to collaborate? Reach out here on GitHub. Let’s build something useful.