Guillermo Teijeiro
Open to remote opportunities

Guillermo Teijeiro

15+ years of experience. Software Developer from Cordoba, Argentina.

Work experience

  1. •

    Senior Developer

    SHIFTA

    Work as a Senior Developer on large scale projects. Build strategic internal solutions for the YPF ecosystem and integrate into multidisciplinary agile teams for Galicia Seguros, driving technology evolution and modernization of their digital platforms.
  2. •

    .NET Developer

    Bitsion

    Technical leadership on high impact projects: ecommerce for Neverland (balance top up and sales) and a full logistics tracking application. Implemented complex architectures using .NET, SQL, MongoDB, RabbitMQ, Neo4j, and Angular. Also participated in planning and building a white label virtual wallet.
  3. •

    .NET Developer Analyst

    DICSYS

    Support and maintenance for critical applications for strategic clients such as QPlus, ensuring operational continuity and efficient incident resolution.
  4. •

    .NET Developer

    Globadlity

    Maintenance and modernization of web application ecosystems using AngularJS, focusing on technology upgrades and code stability.
  5. •

    .NET Developer Analyst

    Sofrecom Argentina SA

    Implemented critical new features for the massive 'Mi Cuenta' application for Personal and built the 'Club Personal Empresa' platform, applying a UX focused approach. Managed corrective maintenance and performance optimization.
  6. •

    Developer

    GEMINUS IT

    Delivered the Single Window project for the Municipality of Cordoba. Built a real time quotes application using SignalR and KnockoutJS, pioneering SPA frameworks at the time.
  7. •

    Developer

    Grupo Prominente

    Participated in the full software development lifecycle. Executed QA and testing processes to ensure delivery quality, along with maintenance and code refactoring tasks.

Projects

Personal projects

Tools and products built from personal initiative.

Files Tools

Files Tools

Console utilities in Python to organize and sanitize large collections of media files (images, videos, and more). The project groups AI assisted tools that classify files, clean names, detect duplicates, and reorganize messy collections automatically and efficiently from the command line.

  • Python
  • CLI
  • IA
  • Script
  • Consola
  • Open Source
ARCA LPG Scraper

ARCA LPG Scraper

Command line tool in .NET 9 that automates downloading PDF vouchers from AFIP's LPG portal. It uses Playwright to reproduce the manual navigation and authentication steps, detects available records, and downloads the documents locally with sanitized filenames to avoid collisions.

  • C#
  • .NET 9
  • Playwright
  • AFIP
  • CLI
  • Consola
  • Open Source
ARCA LPG OCR

ARCA LPG OCR

Python command line tool designed to process and extract structured information from LPG PDF settlements. It combines OCR with text block and table detection to produce outputs like CSV or JSON, normalizing key fields such as buyer, seller, totals, and agricultural details for each downloaded settlement.

  • Python
  • CLI
  • Consola
  • OCR
  • Tesseract
  • Open Source
Telegram Bot

Telegram Bot

Telegram bot built in Python that receives invoice images or PDFs, converts PDFs to images, and extracts key data using Azure OpenAI (vision + structured outputs). The bot replies with a structured JSON containing fields like invoice number, amounts, date, and seller/buyer details directly in Telegram chat.

  • Python
  • Telegram
  • Azure
  • OpenAI
  • OCR
  • Open Source
AI Code Generator

AI Code Generator

Python web app built with Streamlit that acts as an AI assisted code generator. It connects to Azure OpenAI models to apply prompts over custom templates, replace variables in static files, and download the generated code organized by files. Includes handling for different AI models and helpers to clean and structure input text.

  • Python
  • Streamlit
  • Web App
  • IA
  • Azure
  • OpenAI
  • Open Source
Quini6 Bot

Quini6 Bot

Automated Python bot that fetches Quini 6 results from the web, runs periodic scraping, and notifies the user with the latest results. It includes HTTP requests handling, HTML parsing to extract winning numbers, and logic to compare and show changes since the last run.

  • Python
  • Telegram
  • Azure
  • Scraping
  • Open Source

Work projects

Work done in the context of companies and clients.

Sendbox

Sendbox

End-to-end platform for generating, managing, and tracking parcel shipments. I participated as Technical Lead in the development of a full system covering the entire shipment lifecycle: creation, pickup, distribution, and final delivery, including internal company processes. The solution integrates a .NET backend, multiple frontends (AngularJS, Angular, and Ionic), asynchronous messaging with RabbitMQ, Windows services, and advanced traceability with relational and non-relational databases. CI/CD and quality practices were implemented with Jenkins, Octopus, and SonarQube, working under agile methodologies with Code Review, Jira, Scrum, and Kanban.

  • NET .NET
  • TS TypeScript
  • AngularJS
  • Angular
  • Ionic
  • SQL Server
  • MongoDB
  • Neo4j
  • RabbitMQ
  • WS Windows Services
  • GM Google Maps API
  • Firebase
  • Jenkins
  • Octopus Deploy
  • SonarQube
  • Entity Framework
  • Scrum
  • Kanban
  • Bitbucket
White Label Virtual Wallet

White Label Virtual Wallet

Development of a white label virtual wallet integrated with Bibank APIs for managing virtual accounts with CVU. I participated as a Developer implementing the backend in .NET and .NET Core, desktop applications with WinForms, and frontend in Angular. The solution included webhook integration, asynchronous messaging with RabbitMQ, and Windows services for operation processing. We worked with SQL Server and MongoDB databases, applying code quality practices with SonarQube and CI/CD pipelines with Jenkins and Octopus, under Scrum methodology with Code Review and Jira management.

  • NET .NET
  • NET .NET Core
  • MVC ASP.NET MVC
  • WF WinForms
  • Angular
  • SQL Server
  • MongoDB
  • RabbitMQ
  • WS Windows Services
  • WH Webhooks
  • Jenkins
  • Octopus Deploy
  • SonarQube
  • Scrum
  • JIRA Jira
  • CI/CD CI/CD
Mi Cuenta Individuals Full Responsive

Mi Cuenta Individuals Full Responsive

Project developed with Sofrecom Argentina SA between December 2014 and 2015, focused on migrating a previous self service personnel platform to a fully responsive web experience for all screen sizes. The solution consisted of two applications: an ASP.NET MVC web app for the presentation layer (HTML, CSS, and JavaScript) and an ASP.NET Web API application under a RESTful architecture that concentrated the business logic. I participated in architecture design and in the development of the ASP.NET Web API, working under CMMI and Agile methodologies, with Redmine/Jira management and SVN/Git version control.

  • NET .NET
  • C#
  • MVC ASP.NET MVC
  • WEBAPI ASP.NET Web API
  • REST RESTful API
  • HTML HTML
  • CSS CSS
  • JS JavaScript
  • ARCH Software Architecture
  • CMMI CMMI
  • AGILE Agile
  • RDMN Redmine
  • JIRA Jira
  • SVN SVN
  • GIT Git
VU - Single Window

VU - Single Window

Project developed with GEMINUS IT between February and July 2014 for the Municipality of Cordoba. It is a web application that allows citizens to start the business license process online, centralizing the administrative flow in a single platform. The solution was built in ASP.NET 4 with C#, using NHibernate as the ORM for data management and persistence. The project was managed with Redmine and version control with SVN.

  • NET .NET
  • C#
  • ASP4 ASP.NET 4
  • NHIB NHibernate
  • ORM ORM
  • SQL Server
  • RDMN Redmine
  • SVN SVN
BCRA

BCRA

Institutional website built for BCRA with Grupo Prominente, implemented in ASP.NET 3.5 with C# on both front end and back end. The solution consisted of independent ASP.NET pages managed through PECTRA (internal BPM software), integrating Prominente's own framework and WebServices for interoperability between systems. Client side validations were implemented with JavaScript and the database was SQL Server 2008 R2. The project followed CMMI methodology, using TFS as the project manager and repository.

  • NET .NET
  • C#
  • ASP35 ASP.NET 3.5
  • SQL Server
  • JS JavaScript
  • WS WebServices
  • BPM BPM
  • PECT PECTRA
  • CMMI CMMI
  • TFS TFS

About me

My name is Guillermo Teijeiro and I have spent more than 15 years dedicated to software development. My first real contact with programming was at university, where I learned C++, and that is where I discovered that coding was not only interesting to me, but what I truly enjoyed. Over time, that choice became my profession.

Today I work as a Senior Software Developer, mainly with .NET, participating in the design and development of complex systems that need to be stable, scalable, and easy to maintain. Throughout my career I have been part of real business projects, where the focus is not only that the code works, but that it is maintainable and delivers long term value.

I am comfortable working both on backend and frontend, integrating APIs, improving existing architectures, and collaborating with multidisciplinary teams. I especially enjoy solving complex problems, optimizing processes, and turning business needs into clear technical solutions.

I firmly believe in continuous learning and in writing software with judgment and responsibility. My goal is to keep growing as a professional, bring real value to the teams I work with, and build solid products that are worth being proud of.

Guillermo Teijeiro