michal.piekarczyk.xyz

Longer-form posts about whatever I'm exploring.

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  Coldest Feb 15, 2026

  Recently, myself and the rest of NYC went through a cold spell and news outlets reported2 the 13 day stretch of sub-zero weather, ending Feb 6th, was not longer than a 16 stretch in 1881. And this was shorter than a 1963 stretch, but tying a 2018-01-13 streak. But this recent winter sure felt extreme. I know there is a recency bias, but I figured, why not also compare the area under the curve too. So I ranked the coldest 14-day stretches, using available data of the past decade. And then tried to visualize the spans of the coldest years too.

• Looking Forwards Feb 7, 2026

  Email forwarding mystery solved Feeling several facepalms now that my michal@piekarczyk.xyz email finally forwards to my hey.com email inbox. After several sessions of tweaking, the answer was low tech! Registrar forwarding Originally, I setup mail forwarding on my domain registrar. Only $5 a year, okay why not. After proving to my registrar I owned my hey email, I was all set, but tests yielded silence. I spent several chat sessions with a support engineer at my registrar. He pointed out I was missing SPF and DKIM records for my custom domain and so he added those. Those have nothing to do with delivering mail to my address and only help to authenticate mail sent from my domain, but I figured what the heck let’s try something. That did not work.

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  Gardening time Dec 28, 2025

  Life’s a garden, can you dig it? That is what a colleague of mine had said very often when we worked together, about how you need to put time and effort into stuff. You know, get your hands dirty ! Picking up my shovel Today I finally took a first step to trying out this digital gardening concept on Maggie Appleton’s blog0. I came across back on haha I don’t know why but on 2025-07-04 , I guess it was a kind of independence day in my brain, from the march of chronology.

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  Skip the Jetlag Dec 11, 2025

  Came back from a flight from New Delhi , Monday morning, that left New Delhi just after midnight and 16 hours later arriving in New York around 5:30 am. And so far today, Thursday morning, I feel kind of fine, not really jet lagged, in the sense of wanting to wake or sleep at odd hours. The specific strategy I did in attempting to align meal time and sleep time with the destination time zone was to fast the day of the flight until lunch time arrival at my destination. It would have been ideal if I was able to sleep during the red eye though not doing so was also perhaps fine since by the time I crashed on Monday at around 19:00, I had about 16 + 16 + 12 = 44 hours of sleep pressure in the tank. And then when I slept for basically 12 hours, waking at 7 am on Tuesday, and getting the morning sun, I was basically back in my rhythm. And so far, sleep on Tuesday night and Wednesday night was pretty okay.

• Something is not Tracking Dec 10, 2025

  Recently I went on a trip to India where so much was going on I stopped using my meal tracking. And on this trip the other thing that happened was that half the time, I was in a plane, waiting for a plane, or on a bus –or on the back of a Maruti Suzuki offroad Jimny– or otherwise sedentary. And yet, after the brief 10 day trip, I carved off an inch and a half off my waist and dropped over 6 pounds on the scale. (Side note, I know that “intra-day” variability can be high, because I have personally seen a reset of 5 pounds , within a day’s worth of eating, answering the call of nature and exercising, and so on, but “inter-day” variability, should be lower, when you weigh-in at a consistent time of day).

Fleeting notes and thoughts that might take shape later.

• humidifier debugging first try Mar 2, 2026

  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.

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  Immich to vimeo Update Mar 1, 2026

  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.

• Boundary Detection Feb 27, 2026

  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.

• Catalyst Optimizer Pushdown Encounter Feb 25, 2026

  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

• What ends up happening Feb 13, 2026

  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.