The latest articles on DEV Community by Leonardo Rend (@reativazapsoftware). https://dev.to/reativazapsoftware https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4092478%2F65c30603-bd38-4951-8212-1ac8c1c66fc2.png https://dev.to/reativazapsoftware en Leonardo Rend Mon, 24 Aug 2026 14:08:00 +0000 https://dev.to/reativazapsoftware/how-i-built-a-python-flask-pos-system-with-a-mechanical-discount-lock-slider-4m7o https://dev.to/reativazapsoftware/how-i-built-a-python-flask-pos-system-with-a-mechanical-discount-lock-slider-4m7o <p>Hey everyone!</p> <p>I wanted to share a micro-SaaS architecture I've been working on to solve a real retail problem: cashiers burning store profit margins by giving unauthorized discounts.</p> <p>I built <strong>Reativa Zap Pro</strong>, a lightweight web POS register using <strong>Python Flask</strong> and SQLite. </p> <h3> The Solution: Mechanical Slider Lock </h3> <p>Instead of a complex backend permission system, the core feature is a dynamic UI discount slider that mechanically locks and limits input based on customized price ranges defined by the shop manager.</p> <h3> Technical Stack: </h3> <ul> <li> <strong>Backend:</strong> Python 3.x / Flask Framework</li> <li> <strong>Database:</strong> SQLite (zero configuration, standalone <code>.db</code>)</li> <li> <strong>Frontend:</strong> Premium Dark Mode UI with high-contrast Neon Green elements.</li> </ul> <p>I have packaged the entire source code clean, modular, and with an automated <code>.bat</code> initializer script so anyone can deploy it instantly or use it as a robust boilerplate to build their own software business.</p> <p>If you want to check out the clean code structure or grab a commercial license for your own projects, the deployment is live on Gumroad:</p> <p>👉 <strong><a href="https://leonardorend.gumroad.com/" rel="noopener noreferrer">Get the Full Source Code on Gumroad</a></strong></p> <p>Let me know what you think about this UI approach!</p> programming python saas flask