David Tanzer

@dtanzer

Programmer, trainer/coach, climber, #bonsai enthusiast Helping clients create better software and get better at creating software React, TypeScript, Java, Kotlin Pronouns: he/him

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David Tanzer@dtanzer· Jul 13

I wire the sacrificial branches of my #bonsai up to save space, and also because I heard they grow faster when you do that. But the branches of the birch and weeping willow are so soft, they'll come down from their own weight immediately after. So, I built this:

A birch tree in a pond basket, approx. 1.8m tall. Five long bamboo sticks hold the branches up. Background: White wall and an AC.

A weeping willow tree in a pond basket, approx. 1m tall. Five bamboo sticks hold the branches up. Background: White wall and an AC.

David Tanzer@dtanzer· Jul 10

And now it's back on the benches. [3/3]

The bonsai tree, standing on a small bench together with other trees and more plants. Green leaves from a lilac in the background.

David Tanzer@dtanzer· Jul 10

I'm still mad at myself that I planted it at such a shallow angle during the last repot. I think this more upright position works better... Maybe I'll repot it again in sprint, or I'll wait until it becomes pot-bound in 2-3 years, which would probably be better for the tree... [2/3]

The same tree as in the last post, but now with a wooden block under the pot so that it stands more upright.

David Tanzer@dtanzer· Jul 10

Unwired my #juniper #bonsai today. I hope I didn't hurt it when I removed the black ninja tape... [1/3]

Needle juniper bonsai standing on a turntable, wires and black tape still on.

Needle juniper bonsai standing on a turntable, wires and black tape now removed.

David Tanzer@dtanzer· Jun 30

Yesterday I hosted a full-day workshop "Test-Driven Development with and without AI" at the Developer World - DWX conference in Mannheim. Interesting to experience a spectrum of opinions about AI - From "I will write the code myself and maybe let AI help me with the tests" to "Soon we... [1/2]

A flip chart page with two illustrations of the "Universal Architecture" by J.B. Rainsberger

A flip chart page showing the TDD cycle "Red-Green-Refactor" and the words "arrange, act, assert"

A notebook with the time table for the workshop, a small ball with a grumpy face, a laptop, keyboard an mouse, all on a table. Some workshop attendees and a flipchart in the blurry background.

David Tanzer@dtanzer· May 18

I asked #AI to add the AGPLv3 license to a new project, and it did not add the correct text from www.gnu.org/licenses/agp... - IANAL, but some of the changes, though only a few words each, look significant.

Diff-view highlighting the differences.

Left (original from GNU): " An older license, called the Affero General Public License and
published by Affero, was designed to accomplish similar goals. This is
a different license, not a version of the Affero GPL, but Affero has
released a new version of the Affero GPL which permits relicensing under
this license.

The precise terms and conditions for copying, distribution and
modification follow."

Right (AI-Generated): " An older license, called the Affero General Public License and
published by Affero, was designed to accomplish similar goals. This is
a different license, not a version of the Affero GPL, but a separate
license. They are incompatible."

David Tanzer@dtanzer· May 4

My #multiTrunk aronia #bonsai has flowers...

A broadleaf dree with multiple, thin trunks and white flowers at the tops of the trunks. It's in a dark-blue, rectangular bonsai pot, standing on a wooden table in front of a white wall.

David Tanzer@dtanzer· May 3

Lush spring growth on the #bonsai benches...

Many trees and other plants on wooden benches. A flowering lilac and a white wall in the background.

Close up of several trees and other plants on wooden benches. Most of them are early stage projects in pond baskets. All show bright-green leaves. Two little kissing statues in one of the pots.

David Tanzer@dtanzer· Apr 1

#claude code wrote this license for my codeberg.org/dtanzer/drag... fun project. Does that also apply to it's own leaked code? :-D

License (Such As It Is)

This codebase was substantially written by an AI. Whether that means it is owned by anyone is, at time of writing, an open legal question that multiple courts are actively declining to answer. We are not lawyers. We are, however, people who enjoy clarity.

To the extent that any of this is copyrightable by anyone — which may be nobody, or may be the person who typed the prompts, or may be a matter that gets resolved sometime around the heat death of the universe — it is released under the WTFPL.

You know what that stands for.

In adjacent dimensions where this question has already been settled by courts, wizards, or some combination thereof, local laws may vary. We defer to the relevant guild. Void where prohibited by prophecy.

David Tanzer@dtanzer· Mar 25

Full explanation video coming soon - watch this space... codeberg.org/dtanzer/agnt #ClaudeCode #MultiClaude

David Tanzer@dtanzer· Mar 23

On my way to #Switzerland where I'll speak at #VoxxedDays #Zurich vdz26.voxxeddays.ch #vdz26

Selfie of me, sitting in a train. Outside the window: Landscape - A field with some motion blur first, then some trees and distant hills.

A cup of coffee with two packs of sugar and one pack of milk. "Mit Genuss unterwegs" ("Travelling with pleasure") is written on the sugar.

David Tanzer@dtanzer· Mar 20

You know... I really like the "License" section that #ClaudeCode wrote for my #dragon trainer project 😂🤣 codeberg.org/dtanzer/drag...

Screen shot of the following text:

License (Such As It Is)
This codebase was substantially written by an AI. Whether that means it is owned by anyone is, at time of writing, an open legal question that multiple courts are actively declining to answer. We are not lawyers. We are, however, people who enjoy clarity.

To the extent that any of this is copyrightable by anyone — which may be nobody, or may be the person who typed the prompts, or may be a matter that gets resolved sometime around the heat death of the universe — it is released under the WTFPL.

You know what that stands for.

In adjacent dimensions where this question has already been settled by courts, wizards, or some combination thereof, local laws may vary. We defer to the relevant guild. Void where prohibited by prophecy.

David Tanzer@dtanzer· Mar 12

My damson plum does not get a repot this year, but I added some moss seed mix on top of the soil (after I took this picture). Some buds are already opening - Are those the first flower buds since I grew it from seed? Not sure yet, but would be great! #bonsai

A young plum tree in a pond basket. The trunk is still very thin and it has lots of vertical shoots that I will remove later. Background: Our garden (lawn, wall), very blurry.

David Tanzer@dtanzer· Mar 7

#bonsai repotting season has started for me here in #Austria: Some trees started opening their buds and showing some green, which means they are ready for repotting. Did most of the current repots to improve the #nebari, not becaus the trees were pot-bound...

Two little larch seedlings (~ 2 years old) in a pond basket, their main trunk wired to the side and a small branch wired as new top.

Several pots with very small trees, in the front is a cotoneaster. The soil/substrate is white, red and black (from the different mineral substrate types used).

In the foreground, there is a small pond basked with a hornbeam that is just opening the buds, In the background, a larger pond basket with another tree and a meadow.

A freshly repotted weeping willow with some sacrificial branches wired out with silver wire. The background shows a blurry image of our garden.

David Tanzer@dtanzer· Feb 21

Tried to graft some #apple #trees for the first time - "Golden Noble" on a seedling I grew for 2 years now. I know the cuts are not good, but it was the best I could do. Let's hope they grow - for future #bonsai or garden trees...

Some tools I used for grafting: A knife, scissors, rubber tape and cut paste.

Closeup: First grafted tree, with black tape right above the soil and a short, thin twig sticking out from the tape.

Closeup of the two cuts, one on the seedling, one on the new branch. Both cuts are somewhat irregular, which is not ideal.

Close-up of the second grafted tree, black tape around the cuts, a short twig sticking out from that. There is cut paste on the top cut.

David Tanzer@dtanzer· Jan 23

This week, I used @emilybache.com 's "Pipeline Card Game" again to discuss trade-offs and other aspects of CI/CD pipelines. Highly recommended!

Closeup: A hand holding a deck of playing cards and the person is sorting the cards into different stacks. Three small stacks are already on the table.

On a table, there are several cards that form a pipeline. Two hands are visible, the person is moving some of the cards.

Next to the steps of a half-finished pipeline, there are stickies with execution times (2 min, 10 min). Next to the pipeline, there is also an open bag with sweets.

David Tanzer@dtanzer· Dec 22

Vorige Woche durfte ich einen Workshop leiten, der als Kickoff für weiteres technisches Coaching dient. Wir haben über Modern Software Engineering-Praktiken gesprochen und wie wir diese nach und nach etablieren können. #technicalCoaching #technicalAgileCoaching

Im Vordergrund ein Notizbuch, auf dem mehrere Stifte und ein gelber Ball mit Smiley-Gesicht liegen. Im Hintergrund Tische mit Workshop-Materialien wie Stiften, Sticky Notes, ... (unscharf)

Ein Tisch mit Gläsern, Getränken, Sticky Notes, Blöcken, etc.

Eine Flipchart-Seite mit mehreren Diagrammen, die Geschindigkeit über Projektfortschritt zeigen. Kernaussage: Investitionen in kurze Lieferzeiten zahlen sich später aus.

David Tanzer@dtanzer· Dec 17

On my way to a client, where I will facilitate a whole-day workshop tomorrow. This will be a kick-off for several #TechnicalAgileCoaching - sessions next year. BTW I still have some capacity for coaching and training in Q1/2026. If you're interested, contact me via DM or business@davidtanzer.net

A backpack, a large suitcase and a small suitcase are standing in the middle of a room, ready to be picked up.

Notebook with a detailed, hand-written schedule for a two-day workshop. Different colored pens are on the right page.

A small and a large suitcase, open on the floor. They are full of materials for a workshop: Sticky notes, pens, index cards, etc.

David Tanzer@dtanzer· Nov 19

Moved the trees closer to a house, under a roof. There, they are still exposed to the elements, but protected from extreme cold, strong winds and direct sunlight. #bonsai #autumn

Portrait picture showing the bonsai benches under a roof, trees crammed on them.

Landscape picture showing the same bonsai benches under a roof, with trees crammed on them, and the now-empty garden in the background.

David Tanzer@dtanzer· Nov 17

Thanks to github.com/seapear/Affi... I have now #Affinity Designer v2 runnint on Linux! Yay! Now trying the rest of the suite...

Screenshot of the Affinity Designer start screen (showing some tools and the new file selector)

David Tanzer@dtanzer· Nov 10

Was nervt dich gerade an der Arbeit in der Softwareentwicklung am meisten? Was macht dir am meisten Sorgen? In Gesprächen mit anderen, die in der Softwareentwicklung arbeiten (Devs, Testers, Scrum Masters, etc.) bekomme ich immer wieder das Gefühl, viele sind unzufrieden mit der aktuellen... [1/3]

Zwei Personen, die an einem Laptop gemeinsam arbeiten.

David Tanzer@dtanzer· Nov 7

Hello Nürnberg! Getting ready for the #CodeRetreat tomorrow... #gdcr

The old town of Nürnberg, panorama, taken from a above (a high building near Hauptbahnhof).

David Tanzer@dtanzer· Oct 17

I unlocked the next level of "getting old": Glasses for reading.

Picture of me wearing glasses, wearing a blue pullover. In the background, shelves with books and cameras.

David Tanzer@dtanzer· Sep 13

Started editing my next video about #softwareDevelopment and #bonsai. In the mean time, you can watch my previous video, where I try to discuss the questions "Is it unethical to use AI?" and "Is it unethical to NOT use it?" here: youtu.be/1uR8ntgzAYg

A picture of my desk and my computer screens. The larger one of the screens is showing the timeline view of DaVinci Resolve, the smaller one some additional tools. In the forground, you can see a keyboard, a water glass, a coffee cup and some clutter.

David Tanzer@dtanzer· Aug 15

Recording this weekend... #bonsai #softwareDevelopment

A table and a chair in front of a grey background cloth. On the table, there are a small bonsai tree on a turntable, a coffee mug and some tools. Three lights and a camera are pointing at the table. Some bookshelves in the background.

David Tanzer@dtanzer· Aug 4

Started reading this German book about the biology of #trees. It's a text book for biology students, so a little bit hard to read for me (noob), but it's really interesting. #bonsai

A picture of the book. The cover is grey and shows a drawing of a tree and a cell of a tree. The text on the cover says:

R. Matyssek / J. Fromm / H. Rennenberg / A. Roloff
Biologie der Bäume
von der Zelle zur gobalen Ebene
Ulmer UTB

David Tanzer@dtanzer· Jul 9

I have sycamore moth caterpillars on a sacrifical branch of my #maple #bonsai. I guess I should remove them, but I don't want to, since they are really pretty...

Picture of a sycamore moth caterpillar sitting on a maple leave. In the background, there are more leaves and another caterpillar that is slightly out of focus.

David Tanzer@dtanzer· Jun 4

Trying a new, slightly simplified recording setup for an experimental format based on my talk about #bonsai and #SoftwareDevelopment. Not sure if you'll ever see one of the videos - as I've said, it's experimental, and I'm not sure if I can pull it off in a way that I like.

A grey video background in a room full of books. In front of the background, there is a chair and a table. Three video lights and two cameras are pointing to the chair.

David Tanzer@dtanzer· May 26

We visited the national Austrian #bonsai expo last week - A beautiful event!

Monastary with fish ponds and a fountain in the forground. Different bonsai displayed under the arcs of the hallway. Some people in the background.

A large bonsai with bright-green leaves on a red table cloth.

A bonsai with pink flowers and some other plants, with fish ponds and people in the background.

David Tanzer@dtanzer· May 16

I made this animation about sacrificial branches for my talk about #bonsai and #software #development next week. What do you think? Does it make the process and advantages clear?