Short
version.

I build full-stack software. The stuff I care about tends to sit in the gap between "this works" and "this feels right" — the last twenty percent that nobody else wants to finish.

Right now that means Frat House Frenzy. It's a casino slot engine. From the outside it looks like a game; from the inside it's a math problem, a concurrency problem, and a trust problem stacked on top of each other. A 1024-ways engine calibrated to 96% RTP. RNG that the player can verify with a hash. Bonus rounds that resolve in a single server request so the client has nothing to cheat with. That's the job.

What I've learned building it: specificity is everything. A paytable doesn't produce a 96% RTP because you asked nicely; it produces it because you ran five hundred thousand spins and iterated on the blank weights. Integer-cents floor rounding can make your game look like a scam that pays out zero on common wins. A trailing newline in an env var is the kind of bug that costs you a day. The math has to survive contact with reality.

What I care about when I build: the numbers are real, the edges hold up under adversarial use, and the thing feels good the hundredth time you use it, not just the first. Everything else is decoration.

You can reach me at pfeirstein@gmail.com, or via the contact form.