System design, explained in motion.

An amber infected workstation sends blue propagation paths across a dark global network and toward an encrypted-file lock.
Engineering

How WannaCry spread: EternalBlue, the kill switch, and the ransomware

Trace one Windows host through EternalBlue, the kill switch, WannaCry's encryption, worm propagation, forensic response, and the controls that break the loop.

Aug 21, 2026 · 27 min

Pixel-dithered nighttime city grid with amber pickup route, used as the Uber system-design article cover.
Systems

Designing Uber: how to match riders, drivers, and live location in real time

Follow Alice, Maya, and ride_42 through fare estimation, live driver location, matching leases, trip events, and failure recovery.

Aug 09, 2026 · 24 min

Two abstract profile cards connect across a luminous blue bridge into one amber match node.
Systems

Designing Tinder: how two swipes become one safe conversation

A concrete Tinder architecture that separates geo discovery from swipe consistency, turns two likes into one match, and delivers messages safely.

Aug 01, 2026 · 23 min

A centered stadium connected to ticket inventory, payment, queue, and secure infrastructure
Systems

Designing Ticketmaster: how to sell the last seat exactly once

Follow Alice and Bob through search, caching, a Redis hold, payment, and the one database transition that sells the last seat exactly once.

Jul 25, 2026 · 21 min