Design a system that records events in a single globally consistent order across many machines.

The distributed ordering question, the conceptual core of Kafka, replicated logs, and consensus systems. Interviewers want to see you confront the hard truth that physical clocks lie, then reach for the actual tools: a single sequencer, consensus, or logical clocks. Here is that progression.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.