The latest articles on DEV Community by Jonathan Simon (@jonathan_simon_6c4d439215). https://dev.to/jonathan_simon_6c4d439215 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%2F4148331%2F34f31dc3-f274-4f34-8c6b-f6ded64b2fc1.png https://dev.to/jonathan_simon_6c4d439215 en Jonathan Simon Tue, 29 Sep 2026 02:33:16 +0000 https://dev.to/jonathan_simon_6c4d439215/im-16-self-taught-and-i-built-a-fake-transfer-receipt-detector-for-nigerian-businesses-19c3 https://dev.to/jonathan_simon_6c4d439215/im-16-self-taught-and-i-built-a-fake-transfer-receipt-detector-for-nigerian-businesses-19c3 <p>Hi Dev.to 👋</p> <p>I'm Jonathan, 16, from Bauchi, Nigeria. Self-taught developer. This is my first real product.</p> <h2> The Problem I'm Solving </h2> <p>Fake bank transfer receipts are destroying Nigerian small businesses.</p> <p>A buyer sends a screenshot of a "successful transfer" — it looks 100% real. The vendor ships the goods. The money never lands. The vendor loses the goods AND the money, with zero recourse.</p> <p>I've seen one of these fake receipts myself. If a vendor wasn't paying attention, they'd be scammed in 5 seconds.</p> <h2> What I Built </h2> <p><strong>NaijaStack</strong> — a free business automation tool for Nigerian SMEs.</p> <p>Key features:</p> <ul> <li> <strong>AI Fake Transfer Detector</strong> — scans payment receipts (OPay, PalmPay, Moniepoint, GTBank, etc.) and flags fakes: edited fonts, wrong session IDs, doctored amounts</li> <li> <strong>AI Magic Fill</strong> — type "Emeka bought 2 shirts for 15k" and the form fills itself</li> <li> <strong>Order tracking</strong> — New → In Progress → Ready → Paid</li> <li> <strong>Stock management</strong> — auto-decrements when you sell</li> <li><strong>Expense tracker + 7-day P&amp;L dashboard</strong></li> <li><strong>WhatsApp receipts, reminders, and rider dispatch</strong></li> <li> <strong>AI Business Assistant</strong> — ask "how much profit did I make this week?" and get a real answer</li> </ul> <h2> Tech Stack </h2> <ul> <li>Vanilla JS (no framework)</li> <li>Firebase Firestore + Auth</li> <li>Google Gemini API via Netlify Functions (API key never exposed)</li> <li>PWA (installable, works offline)</li> <li>Hosted on Netlify</li> </ul> <h2> What I Learned Building This </h2> <ol> <li> <strong>Structure over features.</strong> My first version had nested event listeners that duplicated orders. Lesson: keep functions clean.</li> <li> <strong>Security is not optional.</strong> I moved my Gemini API key to a Netlify Function after realizing it was exposed in the browser.</li> <li> <strong>Small details matter.</strong> Toasts, skeleton loaders, an onboarding tour — these took 10% of the time and made a 90% difference in feel.</li> </ol> <h2> What I Need Help With </h2> <ul> <li>Security — I'm learning this as I go. Any tips on Firestore rules or API safety?</li> <li>AI prompt engineering — how would you improve the fake receipt detection?</li> <li>Getting my first users — I have zero. Advice welcome.</li> </ul> <h2> Try It </h2> <p>It's free during beta, no card:</p> <p><strong><a href="https://naijastack.netlify.app" rel="noopener noreferrer">https://naijastack.netlify.app</a></strong></p> <p>Feedback welcome — good or bad. I'd rather know what's broken than ship something mediocre.</p> <p>— Jonathan</p> ai javascript firebase showdev