Reverse Mick Jagger

Listening to this Cory Doctorow interview . [1] I like his hypothesis for why the foundation model companies are valued so disproportionately highly, that the aristocratic class really really really doesnt want to depend on the working class and they see a way out to finally do without them. That makes sense! But yea reality is , the current models are really really really good at giving you what you “say” you want, which is far from what you need most of the time. ...

March 8, 2026 · (updated March 9, 2026) · 3 min · 439 words · Michal Piekarczyk

prompt-driven-development

lack of clarity what to do next? write it out as if you were to prompt a LLM tool like ChatGPT , but instead the prompt is for you . Prompting seems to have rewired my brain , over the past three years, to focus into words, into highly descriptive narrative, what I want , knowing my words need to be free of noise. This is to the point now Ill often start writing a prompt in a Chat window or a message to a friend or colleague at work, and Ill stop, realize that writing helped me organize my thoughts and I no longer need to even ask the question. ...

March 4, 2026 · 4 min · 661 words · Michal Piekarczyk

going the manhattan distance

Reading the on bullshit paper. author saying in old days craftsmen did not “cut corners”. looking this up , think that was literally about the road you took, per reading [2]. paved road vs over fields. but hmm, shortcuts are kind of organic rosds not necessarily sloppy. like, we have, planned vs actually useful question here ? Idea can be extended maybe , what are we building anyway. You will not do it perfectly from your first idea. ...

March 3, 2026 · (updated March 7, 2026) · 2 min · 276 words · Michal Piekarczyk

humidifier debugging first try

Just had some first try humidifier debugging results! Daily yay! Hah, debugging stories like this that I have, rarely get resolved quickly. My vornado fan heater that downgraded into just a fan had an issue where I found a workaround that ultimately stopped helping and lucklily the staff at Vornado sent me a replacement so I guess I was under warranty. But for my Honeywell humidifier, I had a pretty lucky result just now. I usually fill the tank in the evening, for a mist to counter the evening dryness from the winter indoor weather. But this morning the tank was full and the orange panic light was on. This light only comes on when the water runs out. So that was weird. ...

March 2, 2026 · 1 min · 165 words · Michal Piekarczyk

Immich to vimeo Update

I was trying to use chat gpt codex to save myself a few minutes, to add two new vimeo rest api parameters, name and description , to my upload script I mentioned earlier3. I encountered a 500 and so I could not create a PR. however the cool thing is that I learned about the git apply capability, which somehow I did not realize existed . But it worked seamlessly, with just taking the patch and git apply codex.patch. ...

March 1, 2026 · 2 min · 266 words · Michal Piekarczyk

Boundary Detection

Follow up to here1, expanding, on the overwhelm of intake you end up with if there are too many voices competing for your time. I want to sharpen what appears to be happening. Yes, your colleagues are asking for help and you dont want to deny them. Yes some production system is breaking, someone else is addressing it, but you have an inkling as to why and you want to save them time on triage. Yes, your colleagues are asking for their pull requests to be reviewed and yes there are also all the other things you said yes to presumably at the start of the sprint. And yes you just attended a meeting reminding you that the next PI planning is just a few weeks away and you should spend some time on refining proposals. ...

February 27, 2026 · (updated February 28, 2026) · 2 min · 410 words · Michal Piekarczyk

Catalyst Optimizer Pushdown Encounter

I ended up learning about how the spark catalyst optimizer performs a so called predicate pushdown, running into this weird issue, simplifying my example below. The behavior was encountered when a df has “left_id”, “free_form” and, where df_ref contains “right_id”, “location” and the column “free_form” contains yyyyMMdd dates only when “location” is “12345” and so thats why a join is performed, start_date = '2024-01-01' end_date = '2025-12-31' (df.join(df_ref, df.left_id = df_ref.right_id, "left") .filter(f.col("location" ) == "12345").withColumn ( "foo_date", f.to date("free_form", "ууууMMdd") ) .where(f.col("foo_date").between(start_date, end_date)) .display()) But mysteriously this crashes when the final start_date, end_date filter is done with ...

February 25, 2026 · (updated March 2, 2026) · 2 min · 295 words · Michal Piekarczyk

What ends up happening

We want to follow the optimal path of the day, not the one using yesterday’s information One reason why plans, I notice for myself, don’t survive, is when there are multiple people waiting on me and also if I have multiple opportunities I have noticed. And also all of this competes with all of the things I have theoretically planned to do in a given day or week or sprint. ...

February 13, 2026 · (updated March 7, 2026) · 6 min · 1170 words · Michal Piekarczyk

Whose Responsibility is Tech Debt

Starting a small note here, around discussions myself and others have been having on my team about whether addressing tech debt should be prioritized explicitly or is it something you just address like you might with local refactors with the so-called boy-scout-rule [1]. Realizing after having several converstions about this lately that there are many diverging opinions on this. I have some teammates who see this as the responsibility of the product team, and others who will tackle it head on like an obstacle in their way of the main task at hand. And a more nuanced middle-ground of colleague who is a fan of The Goal, is that you should not have tech debt in the first place if you “pay it down” in stride as part of your role of implementing whatever the company envisions. ...

February 11, 2026 · 4 min · 657 words · Michal Piekarczyk

Notes on feast for spark

Looking into feast, the open source feature store, and whether there is support for using feast as an interface around parquet and or delta tables, with use in a pyspark batch inference databricks environment. I see that parquet is mentioned in the quickstart2, using parquet as the offline component and using sqlite as the online store component. The offline store component is described as intended for training. Maybe it can be useful for a batch inference case too? ...

February 8, 2026 · (updated February 13, 2026) · 5 min · 914 words · Michal Piekarczyk