Algorithms, Blockchain and Cloud
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Latest posts
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Teaching Kids Programming – The Halting Problem: Paradoxes, Self-Reference, and Why Some Problems Are Impossible to Solve
The Halting Problem proves that no algorithm can determine whether every arbitrary program will terminate. Explore the Barber Paradox, Russell's Paradox, self-reference, diagonalisation, and Alan Turing's elegant proof of undecidability. The Halting Problem: Paradoxes,…
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Split a Photo into a 3×3 Grid with iPhone Shortcuts: Build, Install, Share and Recreate It in Python
You do not need a third-party app to split a photo into a nine-image grid on an iPhone. This post shows how to build an Image Nine-Grid shortcut from scratch, accept photos from the Share Sheet or Photos app, split the original image directly into a 3×3 grid without cropping…
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Microsoft Global Hackathon 2026: One Week to Turn an Idea into Something Real
Over the past couple of years, I have started taking part in Microsoft’s annual Global Hackathon. With only one week to experiment, the goal is rarely to build a production-ready product. Instead, it is about validating an idea, creating a proof of concept, learning something…
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CP/M: The Operating System That Came Before MS-DOS
A look back at CP/M, one of the most influential operating systems before the rise of Microsoft DOS. Its command-line interface and familiar commands such as DIR, TYPE, and FORMAT show just how much early personal computing shaped the systems that followed. CP/M: The Operating…
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From Drag-and-Drop to Directing AI: Faster Coding, but Are We Growing as Developers?
From building interfaces in VB and Delphi to directing multiple AI agents , software development has changed dramatically. This reflection explores the enduring value of RAD, the productivity gains of AI coding, and the challenges of code review and continuous learning. We can…
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When AI Writes the Code, What Skills Do Developers Still Need?
From Chatting to Taking Action: AI Is Turning Yesterday’s Wonders into Today’s Routine Recently, I came across a video from more than three years ago. In it, we were still amazed that ChatGPT could hold a conversation like that. Ask it a question, and it could give a coherent…
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A Google Alert Woke Me Up: Postmortem of a WordPress Security Incident
An unpatched WordPress and plugin vulnerability apparently exposed a Cloudflare credential stored in the database. The attacker then deployed a malicious Worker, hijacked selected blog pages, redirected traffic to gambling websites, and added an unauthorised verified owner to…
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The Controlled Variable Method: Why Good Experiments Change One Thing at a Time?
The controlled variable method is one of the most important principles in scientific experiments and engineering practice. When investigating how one factor affects an outcome, we change that factor while keeping other relevant conditions as consistent as possible. Using…
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Code Is Becoming Cheaper: What Really Matters for Programmers in the AI Era
[caption id="attachment_158064" align="alignnone" width="2048"] Leetcoding/Problem Solving on a Date[/caption] AI is rapidly reducing the cost of writing code. Work that once took programmers hours or days can now be generated, tested, reviewed, and turned into pull requests…
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Linux Disk Space Troubleshooting: Find Large Files and Directories with ncdu
Linux servers can run out of disk space because of growing logs, backups, caches, or Docker data, potentially causing databases, websites, and other services to fail. This article explains how to diagnose disk-space and inode issues using traditional commands such as df, du,…
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Hardening MySQL File Access with local_infile=0 and secure_file_priv=NULL
MySQL needs permission to read and write ordinary database files, but most application databases do not need SQL statements to exchange arbitrary files with the operating system. If a server exists primarily for WordPress or another web application, leaving unused file-transfer…
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Accidentally Deleting Over 18,000 Files with Shift+Delete: Recovering Data from a Surface SSD Using WinFR
While freeing space on my Surface Laptop Studio 2, I accidentally used Shift+Delete to permanently remove the C:\tests directory, which unexpectedly contained photographs from a trip to Switzerland. This article documents my attempts to recover the data using Microsoft’s Windows…
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Teaching Kids Programming – Minimum Number of Perfect Squares via Theorem-guided iterative deepening DFS
This article explores an iterative-deepening recursive solution to LeetCode 279, Perfect Squares. By combining depth-limited search with Lagrange’s Four Square Theorem, we only need to test whether a number can be represented using one, two, or three perfect squares—otherwise,…
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Hardening WordPress: Disable PHP Execution in `wp-content/uploads`
[caption id="attachment_26281" align="alignnone" width="383"] wordpress[/caption] WordPress must be able to write media files to `wp-content/uploads`, but files stored there should never need to execute as PHP. This article explains how to block PHP-like files using a central…
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Turning a Dusty Mini PC into a Home Server: My NUC-8’s Second Life
I gave an unused Beelink SEi8 mini PC a second life by installing Ubuntu and turning it into a home server. It now runs a STEEM node, Node.js applications, databases, a reverse proxy and Cloudflare Tunnel. The article also explains how double NAT allows the NUC-8 to initiate…