Sasha's Site

My name is Sasha, and I've been a passionate programmer my whole life. I started off writing games, and around high school I became deeply interested in software performance. Out of high school, I found myself in the interned at MemSQL (now called SingleStore), working on SIMD-fying the columnar query execution. After that I worked at Voltron Data on Apache Arrow's builtin query engine (Acero) and then moved to Neon for a bit before having the privilege of joining Anthropic.

I basically love all branches of computer science, from hardware and compilers to formal methods and functional programming.

• Not Speeding Up Delta Decoding With Value Speculation
• Is your database fully using your hardware? Probably not!
• Ultrapacking
• Bloom Filters

• Stile: In the 1950s when computers were first invented, programs received big arrays of bytes as input and output other big arrays of bytes. We developed structs and classes to give semantic information about the bytes to make them more interpretable.
  Fast forward to 2026: the average tensor program takes as input a big array of floats and outputs another big array of floats. Stile is the first ever type system for numerical programs! You can write your tiled matmul in whatever language you want, and Stile will verify it did what you want!
• Spork: A Python DSL for writing Metal kernels, because juggling two source files when you just want to write a GPU kernel is just too much work. Integrates with Stile to formally verify your Metal kernels!
• Thork: Same as Spork but for NVIDIA GPUs, wrapping CUDA-C++ and ThunderKittens. Also integrates with Stile so that you can formally verify your ThunderKittens kernels!
• Stealie: A Parallel Runtime Based On Theft! We've all heard of work-stealing thread pools. How about io_uring submission-queue stealing? Or io_uring completion-queue stealing? Or MEMORY STEALING?! No resource is safe when you use Stealie to write your parallel programs.

krassovskysashaATgmail.com
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For a while I was annoyed at all of the AI spam on Hacker News, so I half-jokingly made AI-less Hacker News.