I'm Ramiro Quintana, a Software Engineer & Full Stack Developer. I built Calculadora SIU CrediUPE to solve a small but repetitive problem I encountered while using SIU Guaraní at Universidad Provincial de Ezeiza (UPE). When checking my study plan, I wanted an easier way to keep track of how many free credits I had accumulated. The information was already available in the system, but calculating and filtering it manually was unnecessary work. So I decided to automate it. The idea Calculadora SIU CrediUPE is a Chrome extension that works directly on the SIU Guaraní study plan. Its main purpose is to automatically calculate the number of free credits based on the information already displayed by the system. What started as a small tool to solve a problem I had myself ended up being used by other students as well. Today, Calculadora SIU CrediUPE has surpassed 800 downloads and has more than 250 users. Seeing other people use something I built to solve a specific problem has been one of the most rewarding parts of the project. How it works The extension works by interacting with the existing DOM of the SIU Guaraní page. The general flow is: SIU Guaraní │ ▼ Read the study plan │ ▼ Find relevant subjects │ ▼ Extract credit information │ ▼ Filter the required subjects │ ▼ Calculate total free credits │ ▼ Display the result Instead of asking the user to manually copy information into another calculator, the extension uses the data already present on the page. Working with the DOM One of the most interesting parts of the project was figuring out how the information was structured inside SIU Guaraní. The extension needs to locate the relevant elements, read their content and determine which subjects should be included in the calculation. This required working with JavaScript DOM APIs and making the extraction logic specific enough to recognize the information I needed without interfering with the rest of the page. The goal wasn't to modify how SIU Guaraní works. It was simply to add a small layer of functionality on top of the existing interface. Keeping the extension simple Since the extension is designed for students who are already using SIU Guaraní, I wanted the interaction to require as few steps as possible. The user shouldn't have to: Open another website. Copy their subjects. Enter credits manually. Calculate the result. Go back to SIU Guaraní. Instead, the extension handles those steps automatically. The result is displayed directly within the existing workflow. Why I built it This project started from a very specific problem. Sometimes the most useful software projects aren't large applications. They can be small tools that remove a repetitive task from someone's daily routine. For me, this was also an opportunity to apply what I was learning about JavaScript, browser extensions and DOM manipulation to a real problem. Rather than building another tutorial project, I wanted to create something that I could actually use. From personal tool to published extension After getting the extension working for my own use, I decided to publish it so other students could use it as well. That changed the project from a small local experiment into a real browser extension that had to be packaged, tested and prepared for distribution through the Chrome Web Store. That process also taught me more about the practical side of browser extension development and publishing. What I learned Working on Calculadora SIU CrediUPE helped me understand several concepts that aren't always obvious when learning web development through isolated exercises. Some of the main things I worked with were: JavaScript DOM manipulation Browser extension development Reading and processing information from an existing web interface Data filtering and calculation Injecting UI elements into an existing page Handling different states of a web application Testing the extension against the real SIU Guaraní interface Packaging and publishing a Chrome extension More importantly, it reinforced something I find important about software development: A useful project doesn't have to be complicated. Sometimes a few hundred lines of code can eliminate a repetitive task for an entire group of people. What's next? I want to continue improving the extension as the SIU Guaraní interface evolves and based on feedback from students who use it. I'm also interested in building more small tools that solve specific problems instead of creating software simply for the sake of adding another project to a portfolio. About me I'm Ramiro Quintana, a Software Engineer & Full Stack Developer focused on building web applications, browser extensions, SaaS projects and software solutions under quintana.dev. Calculadora SIU CrediUPE is one of the projects I've built as part of that work. You can see more about my projects at: https://quintana.dev.ar/ CrediUPE: https://quintana.dev.ar/library/siu-upe And the extension is available through the Chrome Web Store.