← shifan

writing

long-form when something broke and i want to remember why. for the one-liners, see things i've learned.

concurrency in practicesep
every concurrency bug i have chased came down to the same question.
concurrency2 min
ordering without global ordersep
crypto-market-pipeline is three go services: an ingester pulling exchange prices, a processor, and a rest api, connected by kafka with redis as the hot store.
kafka2 min
ap2 and x402sep
two protocols got most of the attention in agentic payments over the last year.
protocols2 min
agentic paymentssep
ai agents are starting to spend money.
payments2 min
what inference actually costsaug
inference is a metered utility, and most teams find that out on the first real bill.
inference2 min
why the cross desk has nothing real-time in itaug
the cross desk is four ai analysts that hold a morning meeting at 8:00 central over real options data, then publish a desk brief.
product2 min
finding the bug that let a $70 account send $500aug
the ledger is a weekend project.
debugging2 min