https://aumahinay.dev/ New blog posts and Python for Treasury Work lessons by Butch Mahinay en Tue, 10 Nov 2026 00:00:00 +0800 https://aumahinay.dev/blog/cybersecurity-part-1-how-cyberattacks-work/ https://aumahinay.dev/blog/cybersecurity-part-1-how-cyberattacks-work/ Tue, 10 Nov 2026 00:00:00 +0800 Forget the hoodie-wearing genius. Today's cyberattacks are run like businesses. Learn what security protects, who the attackers are, how a breach unfolds step by step, and why layered defenses work. https://aumahinay.dev/blog/how-to-use-the-rpt-calculator/ https://aumahinay.dev/blog/how-to-use-the-rpt-calculator/ Tue, 10 Nov 2026 00:00:00 +0800 A step-by-step guide to the free Real Property Tax Calculator on this site, with worked examples, and the lessons every property owner should know about discounts, interest and where the money goes. https://aumahinay.dev/tutorials/check-or-series/ https://aumahinay.dev/tutorials/check-or-series/ Tue, 10 Nov 2026 00:00:00 +0800 Compare the receipts recorded today with the booklet issued, and flag missing, repeated or stray numbers. https://aumahinay.dev/tutorials/rpt-penalty-with-decimal/ https://aumahinay.dev/tutorials/rpt-penalty-with-decimal/ Tue, 10 Nov 2026 00:00:00 +0800 See why floats are unsafe for money, then compute 2% monthly penalties with a 36-month cap, rounded correctly. https://aumahinay.dev/tutorials/rcd-summary-with-pandas/ https://aumahinay.dev/tutorials/rcd-summary-with-pandas/ Tue, 10 Nov 2026 00:00:00 +0800 Group collections by collector and fund, list the receipts used, and match collections against deposits. https://aumahinay.dev/tutorials/tamper-evident-log-with-hmac/ https://aumahinay.dev/tutorials/tamper-evident-log-with-hmac/ Tue, 10 Nov 2026 00:00:00 +0800 Seal each log entry with a keyed hash chained to the one before it, so any later edit or deletion shows. https://aumahinay.dev/blog/altos-framework-every-document-has-an-owner/ https://aumahinay.dev/blog/altos-framework-every-document-has-an-owner/ Sun, 08 Nov 2026 00:00:00 +0800 A receipt that belongs to everyone belongs to no one. Every form in custody and every peso in hand needs a named, bonded officer who answers for it. https://aumahinay.dev/tutorials/add-up-daily-collections/ https://aumahinay.dev/tutorials/add-up-daily-collections/ Sat, 07 Nov 2026 00:00:00 +0800 Read the day's official receipts from a spreadsheet export and total them per fund, to the centavo. https://aumahinay.dev/blog/so-close-to-alibijaban/ https://aumahinay.dev/blog/so-close-to-alibijaban/ Thu, 05 Nov 2026 00:00:00 +0800 On Hermano Puli Day, I sat alone on someone else's bangka in San Andres, Quezon, and looked out at an island I have loved for almost two decades. This time, I could not cross. https://aumahinay.dev/blog/why-dev-and-not-com/ https://aumahinay.dev/blog/why-dev-and-not-com/ Thu, 05 Nov 2026 00:00:00 +0800 Most people expect a .com. I chose aumahinay.dev. Here is why, in plain words, and what it taught me about building things that are safe by default. https://aumahinay.dev/blog/coming-home-to-the-farm/ https://aumahinay.dev/blog/coming-home-to-the-farm/ Wed, 04 Nov 2026 00:00:00 +0800 Five years. That is how long it had been since I last set foot on my 3-hectare farm. https://aumahinay.dev/tutorials/getting-started/ https://aumahinay.dev/tutorials/getting-started/ Mon, 02 Nov 2026 00:00:00 +0800 Install Python on Windows or Mac, open the command line, and run a script, with fixes for the usual first errors. https://aumahinay.dev/blog/altos-framework-every-peso-has-a-document/ https://aumahinay.dev/blog/altos-framework-every-peso-has-a-document/ Sun, 01 Nov 2026 00:00:00 +0800 No collection without an accountable form, no release without a voucher. A peso that leaves no paper behind cannot be accounted for. https://aumahinay.dev/blog/first-post-as-acting-treasurer/ https://aumahinay.dev/blog/first-post-as-acting-treasurer/ Thu, 29 Oct 2026 00:00:00 +0800 Two years, two Mayors, a pandemic, a typhoon and an election: what my first post as Acting Municipal Treasurer of Mulanay, Quezon, taught me. https://aumahinay.dev/blog/altos-framework-legality-first/ https://aumahinay.dev/blog/altos-framework-legality-first/ Wed, 28 Oct 2026 00:00:00 +0800 Before we ask how a peso was handled, we should ask whether the law allowed it at all. https://aumahinay.dev/blog/why-i-built-altos/ https://aumahinay.dev/blog/why-i-built-altos/ Tue, 27 Oct 2026 00:00:00 +0800 A treasury system built around one idea: every peso should be accounted for from the moment it arrives to the moment it is reported.