rf.blog

adhd documentation personal

ADHD Diary #009: The Documentation Debt That Won't Pay Itself

I just opened a folder on my laptop and counted. 23 markdown files with titles that include some variant of "FINAL", "v2", "actually_final"

Rene Fichtmueller / 2026-06-12 / ~4 min read

LLM Journey AI from Zero Prompting

Learn to Ask Before You Build

Good AI work is less about magic prompts and more about context, checks, and honest follow-up questions.

Rene Fichtmueller / 2026-06-11 / ~3 min read

fiber cables qa

Cable Lengths Get Lied About. Here's How to Catch It Before It Wastes a Week.

I have a spreadsheet I started in 2023 because I kept seeing the same problem. Pre-terminated fiber patch cords labeled with a length that didn't match the cord.

Rene Fichtmueller / 2026-06-11 / ~4 min read

LLM Journey AI from Zero Cloud AI

It Did Not Start With a Server. It Started With a Chat Window.

The first part of the series: how to start with AI without a computer science degree, without servers, and without pretending you already understand everything.

Rene Fichtmueller / 2026-06-10 / ~3 min read

fiber single-mode multi-mode

Single-Mode vs Multi-Mode in 2026 — The Long Argument, Decided

I worked through this debate three times in three different network organisations. The arguments were always the same. Multi-mode is cheaper. Multi-mode is good enough for short reach. Multi-mode is

Rene Fichtmueller / 2026-06-10 / ~4 min read

fiber datacenter thermal

Your Bend Radius Spec Is Wrong in Hot DC Aisles

The bend-radius spec printed on the jacket of every fiber patch cord is correct. It's also for cold conditions. The number was measured at 23 degrees Celsius in

Rene Fichtmueller / 2026-06-09 / ~4 min read

fiber field-ops contamination

Connector Contamination Is Still the #1 Optical Fault

I've stood next to a senior fiber technician at three in the morning, in a data hall at 32 degrees, watching them mate a patch cord without inspecting

Rene Fichtmueller / 2026-06-08 / ~4 min read

hyperscalers procurement market

The Hyperscaler Procurement Playbook, Reverse-Engineered from Public Filings

I get asked a version of this question several times a year. "How do the hyperscalers actually buy optical modules — what are they doing that we should be doing?

Rene Fichtmueller / 2026-06-05 / ~4 min read

ols dwdm disaggregation

Open Line Systems Are Winning — Slowly, Reluctantly, Inevitably

Every major carrier I spoke with in 2020 told me Open Line Systems was a niche play. Maybe useful for greenfield builds, maybe a defensive negotiating tool, maybe interesting for

Rene Fichtmueller / 2026-06-04 / ~4 min read