Christian Hollinger

Software Engineering, GNU/Linux, Data, ML, and other things

26 Oct 2023

Moving a Proxmox host with a SAS HBA as PCI passthrough for zfs + TrueNAS

1,412 words, ~5 min read

How to move a Proxmox host to a new m.2 SSD when using a LSI SAS HBA card to realize PCI passthrough for HDDs for zfs + TrueNAS.
19 Jun 2023

Building a functional, effectful Distributed System from scratch in Scala 3, just to avoid Leetcode (Part 1)

9,419 words, ~37 min read

Building something that already exist (but worse) so I don't have to think about Leetcode: Bridge Four, a simple, functional, effectful, single-leader, multi worker, distributed compute system optimized for embarrassingly parallel workloads.
08 Apr 2023

Migrating a Home Server to Proxmox, TrueNas, and zfs, or: How to make your home network really complicated for no good reason

7,374 words, ~29 min read

Going from a single, bare metal Debian server to two physical machines, 7 VMS, 5 zfs pools, and a whole bunch of data and networking: An experience. Also, stuff broke.
24 Jan 2023

QGIS is the mapping software you didn't know you needed

4,012 words, ~16 min read

QGIS is incredible: You can build maps that make use of the absolute wealth of public data out there and put Google Maps to absolute shame. This article is doing just that.
08 Sep 2022

Tiny Telematics: Tracking my truck's location offline with a Raspberry Pi, redis, Kafka, and Flink (Part 2)

5,022 words, ~20 min read

Tracking vehicle location offline with a Raspberry Pi, Part 2: Apache Flink, scala, Kafka, and road-testing.
29 Aug 2022

Tiny Telematics: Tracking my truck's location offline with a Raspberry Pi, redis, Kafka, and Flink (Part 1)

5,370 words, ~21 min read

Building custom Linux images, dealing with a 40 year old GPS standard, & trying to shoehorn functional programming into Python: Tracking vehicle location offline with a Raspberry Pi. (Part 1)
01 Jun 2022

Functional Programming concepts I actually like: A bit of praise for Scala (for once)

4,645 words, ~18 min read

Types, type classes, implicits, tagless-final, effects, and other things: Not everything in the world of functional programming is bleak and overly academic. A view on FP & scala concepts someone who loves to complain actually likes.
27 Feb 2022

Scala, Spark, Books, and Functional Programming: An Essay

6,296 words, ~25 min read

Reviewing 'Essential Scala' and 'Functional Programming Simplified', while explaining why Spark has nothing to do with Scala, and asking why learning Functional Programming is such a pain. A (maybe) productive rant (or an opinionated essay).
03 Dec 2021

Building a Data Lake with Spark and Iceberg at Home to over-complicate shopping for a House

9,264 words, ~37 min read

How I build what is essentially a self-service Data Lake at home to narrow down the search area for a new house, instead of using Zillow like a normal person, using Spark, Iceberg, and Python.
12 Aug 2021

Writing a Telegram Bot to control a Raspberry Pi from afar (to observe Guinea Pigs)

1,772 words, ~7 min read

A quick project to write a Telegram chat bot that can control a camera, connected to a Raspberry Pi, to take pictures of things; or: Why I refuse to trust IoT vendors and do everything myself