commit 0000000 (HEAD → main)

Hi, I'm Alex Matias

.NET Software Developer @ CartSys Software · Divinópolis, MG

Available for freelance projects and open to new opportunities

> I build

I turn a shop counter into software: orders, inventory, PDF quotes and WhatsApp messages.

git checkout projects open a PR → CV PDF

$ git show about

About me

$ git diff --stat # what changed, measured before and after

−75%response time of a legacy system: from 40s to 10sCondumig · VB6 + MySQL
−25%fee calculation for 1,608 records: from 7m20s to 5m30sCartSys · Entity Framework
−10%+material waste, with per-machine BI dashboardsCondumig · MySQL + QlikView

commit 0000000

Author: Alex Matias

Date:

I'm a .NET software developer with 4 years of experience building, modernizing and integrating business systems, focused on business rules, data and performance.

Today I work at CartSys on the desktop ERP used by Brazilian notary and registry offices (protests, deeds, real estate and corporate registries). Before that, I spent almost three years in manufacturing, maintaining critical legacy systems and automating factory processes in C#.

On my own, I build management systems for small businesses: auto repair shops, printer supply stores and clothing stores. Each system grows out of the previous one, reusing the shared infrastructure and keeping what is specific to each business separate.

I work mainly with C# and .NET (Windows Forms, WPF, .NET Framework 4.8 and .NET 8), Entity Framework / EF Core, SQL Server, MySQL, PostgreSQL and SQLite, as well as layered APIs (Domain, Application, Infrastructure).

diff --git a/stack b/stack

@@ -0,0 +1,0 @@ everyday tools

C#
.NET 8 / .NET Framework 4.8
Windows Forms · WPF
Entity Framework / EF Core
ASP.NET Core Web API
SQL Server · MySQL · Firebird
PostgreSQL · SQLite
DevExpress
REST APIs · JWT
Docker
Git & GitHub
WiX / .msi installers

$ git log --author=alex

Experience

Each job is a commit in my career, from the most recent to the oldest.

commit 327e83b(HEAD → main)Mar 2026 → present · 7 mos
Software Developer @ CartSys Software
Divinópolis, MG
Development of Cartsys, a desktop ERP for Brazilian notary and registry offices (protests, deeds, real estate and corporate registries), with Finance and electronic service invoice (NFS-e) modules. A solution with more than 75 C# projects.
- Banking integration through a REST API (Unicred): issuing, querying, settling, paying, rescheduling and batch-printing bank slips, with token authentication and HTTP failure handling
- 25% faster fee calculation for 1,608 records (from 7m20s to 5m30s) by removing N+1 queries and tuning Entity Framework
- Cloud database over VPN: critical batch routines with chunked loading, reference data caching, grouped audit logs and multi-row inserts, cutting database round trips without changing results
- Digitally signed electronic ledger: PDF/A, SHA-256 hashing and CMS signatures with a digital certificate
- Electronic service invoices (NFS-e): synchronization with municipal and national providers, with no reissuing and no manual database fixes
- Unified report for the National Council of Justice (CNJ) combining SQL Server and Firebird
- Visual modernization to DevExpress WXI across hundreds of forms
C#.NET FrameworkWinFormsDevExpressEntity FrameworkLINQSQL ServerFirebirdREST APIsSVN
commit 146a966May 2023 → Mar 2026 · 2 yrs 10 mos
Software Developer @ Condumig
Divinópolis, MG
Maintenance of critical legacy systems and development of modern C# solutions, focused on industrial process automation, operational reliability and data quality.
- 75% faster response time (from 40s to 10s) in a legacy VB6 engineering system, through database normalization, new indexes and rewritten MySQL queries
- Automated the printing and industrial control workflow with .NET 4.8, WinForms, Entity Framework and MySQL, removing manual steps
- Over 10% less material waste with per-machine BI tools connecting MySQL and Progress to QlikView and Grafeno
- Meal allowance calculation in .NET 8: reads time-clock reports with EPPlus and applies the attendance rules (80% to 100% tiers) with no manual checking
- A "digital inspector" for weighing: monitors coil weight changes in real time and alerts managers on Telegram when fraud is suspected
- Integration routines in .NET 8, EF Core and MySQL extracting data from Progress (Datasul) for financial reports and billing rules
- Stability and evolution of the legacy Factory, Inventory and Administrative systems in VB6
C#.NET Framework 4.8.NET 8EF CoreMySQLProgress (Datasul)WinFormsDockerArduinoGit
commit cdc3a25Nov 2023 → Dec 2023 · 1 mo
Freelancer @ Fiverr
Remote
A C# and WinForms application that took in text and automatically formatted it to the client's specific needs.
C#WinForms
commit 3d6448cJul 2022 → Feb 2023 · 7 mos
Software Developer @ Petrarca Software
Divinópolis, MG
Modernization of the company's management system, with new C# modules and maintenance of the VB.NET legacy code.
- New C# .NET modules with WPF (MVVM), Entity Framework and SQL Server, with clear separation of concerns
- Ported critical libraries from VB.NET to C#, improving performance and readability
- Rebuilt the management reports module with Crystal Reports
C#.NET Framework 4.5.2WPFMVVMSQL ServerVB.NETCrystal ReportsBitbucket

$ git log --grep=education

commit b912aebJan 2023 → Jul 2026
Bachelor's in Computer Science @ Anhanguera Pitágoras

$ git tag --sort=-creatordate

Certificates

Each certificate is a released version. Click to verify it.

$ ls ~/repos

Projects

Business systems, APIs and web tools, from the shop counter to the browser.

GestaoComercial

private

Desktop system for stores that sell products and also service their customers' equipment. First deployed at a toner, printer and stationery store.

C#.NET Framework 4.8WinFormsSQLitePostgreSQL

details

GestaoModa

private

Sales and inventory for clothing stores: keyboard-driven POS, size and color grid, store credit, exchanges, cash register and 22 reports. Rebuilt in .NET 8 on top of GestaoComercial.

C#.NET 8WinFormsEF CoreSQLitePostgreSQL

details

pdf-para-epub

public

Online PDF to EPUB converter for reading on Kindle, Kobo and reading apps. Static front end on GitHub Pages and a Python API running Calibre in a Docker container.

PythonFastAPIDockerCalibreJavaScript

details code demo

ProjetoOficina

private

The system that started the family: work orders, customers and vehicles for auto repair shops.

C#.NET Framework 4.8WinFormsEF CoreSQLitePostgreSQL

details

CriadorInstalador

private

A desktop tool that builds the .msi installer for a Windows Forms system, with Portuguese setup screens and a shared data folder.

C#WiXMSIWinForms

details

LionFinance

private

Personal finance API in ASP.NET Core organized in layers: Domain, Application, Infrastructure and API. Work in progress.

C#ASP.NET CoreEF CoreClean Architecture

details

$ gh pr create --base alex

Let's talk

A proposal, a job opening or an idea: open a pull request.

Hi, I'm Alex Matias

Software Developer @ CartSys Software

Software Developer @ Condumig

Freelancer @ Fiverr

Software Developer @ Petrarca Software

Bachelor's in Computer Science @ Anhanguera Pitágoras

Fundamentos do JavaScript

Introdução ao ASP.NET Core Identity

Fundamentos do C#

.NET Developer Fundamentals (carreira)

Sites Responsivos

Aplicando Orientação a Objetos em Projetos Reais com C# 11 e .NET 7

Dominando Injeção de Dependência

Aplicações Mult-Tenant com Entity Framework Core

Fundamentos do Event-Driven Architecture

Fundamentos dos Microsserviços

Segurança em APIs ASP.NET com JWT e Bearer Authentication

Fundamentos da Orientação a Objetos

Refatorando para testes de unidade

Modelando Domínios Ricos

Fundamentos do Azure, Git, GitHub e DevOps

Fundamentos do ASP.NET 6

Fundamentos do Blazor Server

Fundamentos do Blazor Web Assembly

Fundamentos do Blazor com .NET 8

Progressive Web Apps com Blazor Web Assembly

Fundamentos do Entity Framework

Acesso à dados com .NET, C#, Dapper e SQL Server

Fundamentos do SQL Server

Uma visão geral sobre o ASP.NET Razor Pages

SAP Crystal Reports - Do Básico ao Avançado

Curso Programador

C# COMPLETO Programação Orientada a Objetos

GestaoComercial

GestaoModa

pdf-para-epub

ProjetoOficina

CriadorInstalador

LionFinance