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.

• From the Trenches May 2, 2026

  Riffing off of , https://michal.piekarczyk.xyz/note/2026-03-04-prompt-driven-development/ , and the famous Do Learn Show Loop , and also the ODSC conference I just attended and also squarely on a few topics Nate B Jones has been covrring lately on career visibility , much extending what I think Steve Huynh has introduced me to with his brag docs a few years ago, because work iterates and becauase everyone loves a story, especially interviewers, we should extend the STAR and brag doc styles to be more punctuated, more colorful, still as accurate as possible.

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  ODSC Notes May 1, 2026

  I just finished a trip to attend the ODSC conference in Boston, leaving without really understanding where we are on the hype cycle of Agentic AI . But on the flight back, I read on article2 where Rogé Karma was walking back the stance he had about the AI bubble given new revenue data. The conference gave me a lot of confidence that regardless of what benefit agent AI will ultimately have, there was now no doubt that companies and individuals who do not upskill will fill behind in one way or another. But the article put down some numbers about the new revenue that Anthropic, open Al cursor and the data center companies they rely on, Microsoft, Google, Amazon, Core weave, were now recently experiencing, taking them perhaps, out of bubble territory.

• Rain Gaps Apr 30, 2026

  An micro planning anecdote On a trip to Boston, for the ODSC east [1], earlier this morning, on the lasy day of the conference, I experienced a brief perhaps common Boston weather decision tree phenomenon. It was raining so I was trying to figure out whether to walk to the ODSC convention center, a mile away, or take rideshare. I have really been enjoying the clean fresh Boston air so I wanted to get as much outdoor time here before going back to my polluted NYC home. And I wanted to grab a Starbucks coffee too because the convention center coffee was terrible yesterday and I got a withdrawal headache all day yesterday because I had no access to coffee. I realized by looking outside my hotel window the rain was yea really coming down hard. And I didnt want to be walking around in sloshing wet shoes all day at the conference. I thought hmm , I wish I had packed my REI rain pants. A thought materialized, hmm maybe I could walk to the nearest starbucks and then take rideshare from there. At least I packed the REI rain jacket. It is a true Impermeable! Also, I realized I packed my huaraches, so I could wear those instead and pack my shoes into my day pack. Then pants would probably dry and I will be with dry socks at least!

• The Hero's Safety Net Apr 27, 2026

  I had written about my chaos earlier1, mentioning HBO’s take on ED triage in The Pitt as well. But havijg watched Marty Supreme recently , here is a thought on chaos when it has purpose. Marty says in a especially chaotic scene, about a dog, to Rachel, who likely bears his child, that he has a purpose and he does not know whether she does, and he has to see it through.

• N of 1 Apr 26, 2026

  Seedling of a thought, inspired by the AI Snake Oil Book [1], the Andy Galpin interview with Dr Herman Pontzer I noted [2] as well as some recent conversations , as well as the Mercenary post from earlier, there is an N of 1 idea brewing in my mind. The majority of per person data science is not highly accurate but it is good enough for aggregate population level stats. Maybe we can get the aggregate lift here, which is related to lift of a better model say but not quite the same thing. It would be more like an aggregate financial benefit like population level insurance risk mitigation, say. A dollar lift perhaps.