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 9, 2026) · 4 min · 681 words · Michal Piekarczyk

The Good the bad and the ugly of AI benefit shortfalls

I’m reading AI Snake Oil, and the authors intro by saying they will focus on the examples of AI that harm and they will not include the ones that benefit society. But it is not straightforward to create a list of the good examples. I think one of their examples in the good column was autocorrect. But auto orrect is a good example of where you can’t just sprinkle AI on a problem to solve it....

February 8, 2026 · 4 min · 734 words · Michal Piekarczyk

More Is Less

Listening Nate B Jones here1 to the end. Thought I heard him refer to productivity gains. Had to rewind that to hear it again. every single agent you can run in parallel, multiplies your productivity. But does that translate to value? Recently, I’ve been reading the Healthcare Handbook2, where I (re)learned that “productivity” has a specific meaning to labor economists. Productivity is your output given your input. HH authors further cite this piece4....

February 6, 2026 · (updated February 7, 2026) · 2 min · 313 words · Michal Piekarczyk

Iteration Planning

Notes, reading this article. Has some zingers in here , hah! The iron cross, maybe without one leg? You can’t cheat the scope–time–quality triangle. If we try to fix time and scope, quality takes the hit. In a developer-facing product, degraded quality means support escalations, technical debt, and broken trust. Like any debt, technical debt must be paid back, and its interest compounds over time. I have heard many variations of this....

February 1, 2026 · (updated February 7, 2026) · 2 min · 390 words · Michal Piekarczyk

do you have a flag?

no flag no country Steve Huyhn (aka A Life Engineered ), discusses here , https://youtu.be/oLzj67H-OHo , a few career concepts he says he had to unlearn. One being about hoping if he does good work, it will surely get noticed. But he points out thats highly unlikely to happen. His alternative is to get better at self promoting, starting gently if youre not a natural braggart, highlighting the work of others and then slipping in alongside something you did too, in some email say or chat message....

January 31, 2026 · (updated February 2, 2026) · 3 min · 545 words · Michal Piekarczyk