Mateo's Tech Puzzles
A blog where I post solutions to problems Google had no answer for, plus tech tips from my personal and professional life as a developer.

I migrated this blog from Ghost to Astro using only my phone
Ghost in Docker on an Oracle Cloud VM became a static Astro site on Cloudflare — no CMS, no database, no server. The whole migration ran on the very machine it was replacing, driven from a phone in about an hour of my own time.

How I Rewrote a Kindergarten Website from Static HTML to WordPress
Rebuilding a kindergarten website that had not been touched in a decade: static HTML first, then a migration to WordPress, with 90–95% of the work done by AI tools.

My own Matrix Fortress for Private AI Conversations
Self-hosting a Matrix homeserver on Synapse and PostgreSQL for private conversations with an AI assistant: schema permissions, collation, and a client that would not cooperate.

Fixing the Endless Battery Problem with Zamel RGT-01
Five Zamel RGT-01 radiator heads eating batteries every month or two, swapped for 230 V actuators driven by Shelly 1 Mini Gen4 and a generic thermostat in Home Assistant.

How can I receive a notification if the UV lamp in the basement stops working?
A UV lamp in a water purification station stops at random and nobody notices. A Wemos D1 mini with a photoresistor, ESPEasy, Cloudflare Pages and Pushover fixed that.

Flashing Wemos D1 mini pro is not that easy if the cable is not right
Windows refused to recognise a USB-C Wemos D1 mini pro no matter which driver I installed. The board had power all along — the cable was the problem.

Mystery issue, simple solution - a story about upgrading to Windows 10
Windows 10 setup failing with 0x8007025D-0x2000c in the SAFE_OS phase. It was not the antivirus, the drive or the drivers — it was one checkbox on the bootable USB drive.

I'm back!
After four and a half years the blog is back — this time in a Docker container on a Raspberry Pi, with backups that make the whole setup recreatable in an hour.

Copying terabyte of data from hard drive to Google Drive in Ubuntu - story of how I loved Rclone
Syncing a terabyte from a hard drive to Google Drive on Ubuntu: why the web upload and the FUSE mounts fell short, and how Rclone finally did the job.

Mendeley and Office 2007 - what could go wrong?
Mendeley's Word plugin renders a '}Bibliography' header and duplicates the bibliography in Office 2007. Office 2007 is not supported — here is the workaround anyway.

Using GitLab Container Registry in AWS ECS - this took me a while...
CannotPullContainerError when ECS pulls a private image from the GitLab Container Registry: a deploy token, a Secrets Manager entry and the right task execution role.

When fiancé wants to play The Sims 3 on fresh Windows 7
MSVCP100.dll is missing when The Sims 3 starts on a fresh Windows 7. Which Visual C++ redistributables actually need installing, and in which architecture.

Do you remember that motherboard has CR2032 battery?
A Dell OptiPlex 990 that would not boot Windows 7 and kept forgetting the time. One dead CR2032 battery, and a SATA mode reset to RAID.