PostHog's hard problem is not adding another tool. It is making analytics, replay, flags, experiments, and customer data keep the same meaning in one stack. The value is the event contract, not the screen count. #SystemsLiteracy #DataEngineering

At a flight-booking platform, our fix had two halves: a hold that spans the whole checkout, and reconciliation that compares bookings with inventory. I treat them as one control now. Prevention alone left two correct-looking bookings and no error. #SystemsLiteracy

OpenResearch points at a useful portability unit: the recorded run. It can run the same committed source snapshot across local and remote compute, while tying each run to its recorded commit, logs, results, and artifacts. #SystemsLiteracy #MLOps

A support ticket was the first sign, even though the replicas had already converged. In Cassandra, the cluster agreed again after anti-entropy copied the surviving state back. I do not treat convergence as proof of correctness. #SystemsLiteracy #Cassandra

LinkSwift is a JavaScript userscript for direct links, UI changes, and multiple downloaders across eight cloud drives. The interesting part is operational: once one client script becomes the glue across services, distribution and updates are part of the design. #SystemsLiteracy